US Center For Disease Control (CDC) Report: US Birth Data (2008)

8/4/2019 US Center For Disease Control (CDC) Report: US Birth Data (2008)

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National VitalStatistics ReportsVolume59,Number1 December8,2010

Births:FinalData for2008byJoyceA.Martin,M.P.H.;BradyE.Hamilton,Ph.D.;PaulD.Sutton,Ph.D.;StephanieJ.Ventura,M.A.;T.J.Mathews,M.S.;andMichelleJ.K.Osterman,M.H.S.,DivisionofVitalStatisticsAbstract

ObjectivesThis report presents 2008 data on U.S. birthsaccordingtoawidevarietyofcharacteristics.Dataarepresentedformaternal demographic characteristics including age, livebirth order,raceandHispanicorigin,maritalstatus,attendantatbirth,methodofdelivery, and infant characteristics (period of gestation, birthweight,and multiple births). Birth and fertility rates by age, livebirth order,race and Hispanic origin, and marital status also are presented.Selecteddatabymothersstateof residenceareshown,aswellasdata on age of father. Trends in fertility patterns and maternal andinfantcharacteristicsaredescribedand interpreted.

MethodsDescriptive tabulations of data reported on the birthcertificates of the 4.25 million births that occurred in 2008 are pre sented.Denominatorsforpopulationbasedratesarepostcensalesti matesderived from theU.S.2000census.

ResultsAtotalof4,247,694birthswereregisteredintheUnitedStatesin2008,2percent lessthan in2007.Thegeneralfertilityratedeclined1percentto68.6per1,000.Theteenagebirthratedeclined2percentto41.5per1,000.Birthratesforwomenaged20to39yearsweredown13percent,whereasthebirthrateforwomenaged4044rose to the highest level reported in more than 40 years.The totalfertilityratedeclined2percentto2,084.5per1,000women.Allmea suresofunmarriedchildbearingreachedrecord levels40.6percentofbirthsweretounmarriedwomenin2008.Thecesareandeliveryraterose again to 32.3percent. The preterm birth rate declined for thesecondconsecutiveyearto12.3percent;thelowbirthweightratewasdownveryslightly.Thetwinbirthrateincreased1percentto32.6per1,000; the tripletandhigherordermultiplebirthratewasstable.Keywords:birthcertificatecmaternaland infanthealthcbirthratescmaternalcharacteristics

Highlights+ Atotalof4,247,694birthsoccurredtoU.S.residentsin2008,a

declineof2percent from the recordnumber reported for2007.Birthsweredownamongeachofthe largestraceandHispanic

origin groups: nonHispanic white, nonHispanic black, andHispanic.

+ Thegeneral fertility ratedeclined1percent to 68.6birthsper1,000womenaged1544years.Thetotalfertilityratedeclined2percent, to2,084.5per1,000women.

+ Birthratesdecreased forwomen inallagegroups from15through39yearsbut increased forwomen in their40s in2008comparedwith2007.Thebirthrateforwomenaged4044wasthehighestreported inmore than40years.

+ ThebirthrateforU.S.teenagersaged1519fell2percent in2008,to41.5per1,000,reversingabrief2yearincreasethathadhalted the longterm decline from 1991 through 2005. Ratesdeclinedforteenagesubgroupsaged1517and1819andformost raceandHispanicorigingroups.

+ Childbearingbyunmarriedwomencontinued to rise in2008.Thenumberofbirthsandthebirthrateeachincreased1percentor less, while the percentage of births to unmarried womenincreased to40.6percent.

NOTE: Triplet/+ births are births in t riplet and higher-order multiple deliveries.SOURCE: CDC/NCHS, National Vital Statistics System.

Rateper100,0

00bi

rths

0

50

100

150

200

2008200520001995199019851980

Figure1.Triplet/+birthrates:UnitedStates,19802008

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICESCenters for Disease Control and Prevention

National Center for Health StatisticsNational Vital Statistics System


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2 NationalVitalStatisticsReports,Volume59,Number1,December8,2010

DemariusV.MillerSupervisoryTechnicalWriter-Editor

TheDivisionofVitalStatistics thanksDemariusMilleruponherretirement fromNCHSfor thehundredsofvitalstatisticsreportsshehasenhanced through

hergreat talent,skill,andgoodhumor.


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3NationalVitalStatisticsReports,Volume59,Number1,December8,2010+ Thecesareandeliveryrateroseforthe12thconsecutiveyear,

by2percentto32.3percentofallbirths.Thecesareanratehasrisen56percentsince1996,buttherateof increaseisslowing.

+ The preterm birth rate (less than 37 weeks) declined for thesecondstraightyear,by3percent to 12.3percent.Mostof thedeclinewasamong latepretermbirths (3436weeks).

+ Thelowbirthweight(LBW)ratewasdownveryslightly,from8.22to

8.18

percent.

The

LBW

rate

had

been

rising

fairly

steadily

over

the last twodecades.

+ Thetwinbirthrateincreased1percentto32.6per1,000birthsin 2008, the highest rate on record. The twinning rate rose70percentbetween1980and2004butwasstablefor20042006.The2008triplet/+birthratewas147.6per100,000.Thetriplet/+birthrateclimbedmorethan400percentfrom1980through1998but isdown24percent from the1998peak (Figure1).

IntroductionThisreportpresentsdetaileddataonnumbersandcharacteris

tics

ofbirths

in

2008,

birth

and

fertility

rates,

maternal

lifestyle

and

health characteristics, medical services utilization by pregnantwomen,andinfanthealthcharacteristics.Areportofpreliminarybirthstatistics for 2008 presented data on selected topics based on asubstantialsample(99.9percent)of2008births(1).Inadditiontothetabulations included in thisreport,moredetailedanalysis ispossibleby using the natality publicuse file issued each year. The data filemay be downloaded from http://www.cdc.gov/nchs/data_access/Vitalstatsonline.htm and is available on CDROM upon request (2).Beginning with 2005, the publicuse file no longer includes geo graphic detail; a file with this information may be available uponspecial request (3).Aselectionof tableswithdetaileddata forprioryears isavailable from theCenters forDiseaseControlandPreven tions(CDC)NationalCenterforHealthStatistics(NCHS)website(4):http://www.cdc.gov/nchs.

Adataaccessandanalysistool,VitalStats,isalsoavailablefrom:http://www.cdc.gov/nchs/VitalStats.htm (5). VitalStats includes birthdatafor1990through2008withaccesstointeractive,prebuilttablesandtheabilitytobuildtablesusingmorethan100variablesfromthenatalitypublicuse filesand geographic information bystate and forcountieswithpopulationsof100,000ormore.VitalStatsalsoincludesinteractivechartingandmapping tools.1989and2003revisionsofU.S.StandardCertificateofLiveBirth

This report includes 2008 data on items that are collected onboth the1989 revisionof theU.S.StandardCertificateofLiveBirth(unrevised)andthe2003revisionoftheU.S.StandardCertificateofLive Birth (revised). The 2003 revision is described in detail else where(6,7).TwentysevenstatesandoneterritoryCalifornia,Colo rado, Delaware, Florida, Georgia, Idaho, Indiana, Iowa, Kansas,Kentucky, Michigan, Montana, Nebraska, New Hampshire, NewMexico,NewYork,NorthDakota,Ohio,Oregon,Pennsylvania,SouthCarolina, South Dakota, Tennessee, Texas, Vermont, Washington,andWyoming,andPuertoRicohad implemented the revisedbirthcertificateasofJanuary1,2008.These27states(excludingPuertoRico) represent65percentofallU.S.births.

Thisreportpresents informationonselecteddata itemscompa rablebetweenthe1989and2003birthcertificaterevisions.Anumberoftopicspresentedinthisannualreportinpreviousyears(8)dayofbirth,monthofbirth,sexratio,weightgainduringpregnancy,pregnancyrisk factors, obstetric procedures, Apgar score, and congenitalanomalieswillnolongerbediscussedeachyearbutwillbepresentedoccasionally.Detailed tabulationson these topicsareavailable fromInternetTablesI2, I3, I5,and I6;see ListofDetailedTables.

Keydataitemsnotcomparablebetweenthe1989and2003birthcertificate revisionseducational attainment, prenatal care, tobaccouseduringpregnancy,andtypeofcesareanandvaginaldelivery,aswell as data exclusive to the 2003 birth certificate revision (e.g.,neonatalintensivecareunitorNICUadmission,diabetestype)willbepresented in an upcoming report; tabulations on these topics areavailable in theUserGuide to the2008NatalityPublicUseFile(9).Anearlierreportpresentedselectedinformationexclusivetothe2003revision for2006(10).

Beginning with the 2007 data file, items exclusive to the 1989certificaterevision(e.g.,maternalanemia,ultrasound,andalcoholuse)arenot included in thenatalitypublicusedata files.Thesedataareavailableuponrequest.Methods

Datashown inthisreportarebasedon100percentofthebirthcertificatesregisteredinallstatesandtheDistrictofColumbia.Morethan99percentofbirthsoccurring in thiscountryare registered(9).Tables showing data by state also provide separate information forPuertoRico,Virgin Islands,Guam,AmericanSamoa,andCommon wealth of the Northern Marianas. These areas, however, are notincluded in totals for theUnitedStates.

RaceandHispanicoriginarereportedindependentlyonthebirthcertificate.IntabulationsofbirthdatabyraceandHispanicorigin,datafor Hispanic persons are not further classified by race because themajorityofwomenofHispanicoriginarereportedaswhite.Mosttablesin this report show data for the categories of nonHispanic white,nonHispanicblack,andHispanic.Dataarealsopresented insometablesforAmericanIndianorAlaskaNative(AIAN)andAsianorPacificIslander(API)birthsandforfourspecificHispanicsubgroups:Mexican,PuertoRican,Cuban,andCentralandSouthAmerican,and foroneadditionalsubgroup:otherandunknownHispanic.DataforAIANandAPIbirthsarenotshownseparatelybyHispanicoriginbecause themajorityofthesepopulationsarenonHispanic.Textreferencestoblackbirthsandblackmothersorwhitebirthsandwhitemothersareusedinterchangeably forease inwriting;see TechnicalNotes.

The2003revisionof theU.S.StandardCertificateofLiveBirthallows thereportingofmore thanonerace(multiple races) foreachparent(6)inaccordancewiththerevisedstandardsissuedbytheOfficeofManagementandBudget(OMB)in1997(11).SeeTechnicalNotesandtheUserGuide(9)fordetailedinformationonthe2007multipleracereportingareaandmethodsusedtobridgeresponsesforthosewho reportmore thanonerace toasingle race.

For information on levels of incomplete reporting by state, seeTechnicalNotes.Forinformationonthemeasurementofdataitemsshown in this report and the Internet tables, imputation techniquesused,computationofderivedstatistics,anddefinitionsof terms,seetheUserGuide(9).
http://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchshttp://www.cdc.gov/nchs/VitalStats.htmhttp://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI06http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI06http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI06http://www.cdc.gov/nchshttp://www.cdc.gov/nchs/VitalStats.htmhttp://www.cdc.gov/nchs/data_access/Vitalstatsonline.htmhttp://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI06http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI02


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4 NationalVitalStatisticsReports,Volume59,Number1,December8,2010DemographicCharacteristicsBirthsandbirthratesNumberofbirths

In2008,atotalof4,247,694birthswereregisteredintheUnitedStates,

2percent

less

than

the

4,316,233

births

in

2007,

which

was

thehighestnumberofbirthseverreported intheUnitedStates(4,8)(Tables1and5;Figure2).Births in theUnitedStateshadgenerallyincreased from 1998 through 2007. Despite the drop from 2007 to2008, thenumberof 2008birthswas stillgreater than for anyyearfrom1962 through2005.

The number ofbirthsdecreased for the three largest raceandHispanicorigingroupsin2008:down2percentfornonHispanicwhiteand Hispanic women and 1percent for nonHispanic black women.Births toAPIandAIANwomendidnotsignificantlychange in2008.BirthsalsodecreasedforthespecifiedHispanicgroupsofMexican(by5percent)andCentralandSouthAmerican (by8percent).Births toPuerto Rican and Cuban women did not significantly change. (SeeTables114andInternetTableI1fornationalandstatedatabyage, live-birthorder,andraceandHispanicorigin.)Crudebirthrate

The crude birth rate in 2008 was 14.0 live births per 1,000persons (total population), 2percent lower than the rate in 2007(14.3) (Tables1and5).Fertilityrate

Thegeneralfertilityrate(GFR)in2008was68.6livebirthsper1,000womenofchildbearingage(1544years),1percentlowerthanin 2007 (69.5) (Tables1 and 5; Figure2). The GFR for the UnitedStates had generally increased from 1998 through 2007. Ratesdeclined 1percent for nonHispanic white and nonHispanic blackwomen and 3percent for Hispanic women (Tables1 and 5). ThefertilityratesforAPIandAIANwomendidnotsignificantlychangein2008.AmongspecifiedHispanicgroups,therateforMexicanwomendecreased 8percent in 2008, while the rate for other Hispanicwomen (Central and South American and unspecified Hispanicgroups)increased11percent;seeTechnicalNotesfordiscussionoftheincreaseinbirthstootherHispanicwomen.ThefertilityratesforPuertoRicanandCubanwomendidnotsignificantlychange.

Ageof

mother

TeenagersThe birth rate for U.S. teenagers declined 2per

centin2008to41.5birthsper1,000womenaged1519.Thedeclinefollows a brief 2year increase of 5percent that interrupted thelongterm, 34percent reduction in teenage childbearing from 1991(61.8per1,000)through2005(seeTablesAand24,6,and7)(12).Thatdeclineaveragedabout3percentperyear from1991 to2003,and thenslowed to1percentannually through2005.

Among teenagers under age 20, the rate for ages 1014 wasunchangedat0.6birthsper1,000.Thenumberofbirths to thisagegroupdropped7percent in2008 from2007, to5,764, the fewest inmore thanhalfacentury(5,316 in1953).

The birth rate for teenagers aged 1517 declined 2percent in2008from2007,to21.7per1,000,justslightlyhigherthantherecentlowof21.4in2005(TablesAand4).Theratehadincreased3percentfrom2005through2007,interruptingthe45percentdeclinereportedfor19912005.Thatdeclineaveragednearly5percentannuallyduring19912002andthenslowedtoabout3percentperyearthrough2005.

Thebirthrateforolderteenagersdropped4percentin2008,to70.6per 1,000aged1819.The rate haddeclined26percent from1991(94.0per1,000)through2005(69.9)beforerising6percentfrom2005 through2007.

Among race and Hispanic origin groups, birth rates declined2percenteach fornonHispanicwhiteandnonHispanicblack teen agers from 2007 to 2008 (TableA and Figure3). The rate for APIteenagersdropped4percent,whiletherateforHispanicteenagersfell5percentto77.5per1,000,lowerthanforanyyearsince1989(100.8)whentheratesforHispanicteenagersfirstbecameavailable.Thebirthrate forMexican teenagersalso fell toahistoric low,78.7per1,000(Table8).Thechange forAIAN teenagerswasnotsignificant.

Recentlyreleasedfindingsfromthe20062008NationalSurveyofFamilyGrowth(NSFG)indicatelittleornochangeinsexualactivityandcontraceptiveuseamongadolescentsorinattitudestowardsexualactivityandchildbearingamongteenagers.Likewise,biennialdatafromCDCs19911999YouthRiskBehaviorSurveys (YRBS) forschoolaged youth indicate limited or no change in the majority of thesebehaviors in recentyears (13,14).TheseNSFGandYRBS findingsshowing no recent changes in sexual risk behaviors contrast withpreviouslyreportedlongtermdeclinesinriskybehaviorsamongteen agers from the early 1990s to the mid2000s and may provide thecontextforthemodestchangesinteenagechildbearinginrecentyears.WiththereleaseofthenextroundofNSFGin2011,whichwillcovertheperiodof20062010,itshouldbepossibletoassessthesefactorsin more detail and for age and race and ethnicity subgroups ofteenagers.

Women in their20sThebirth rate forwomenaged2024declined3percentin2008,to103.0birthsper1,000womenfrom106.3in2007.Exceptfora3yearupturnfrom2004through2007,thisrate

NOTE: Beginning with 1959, trend lines are based on registered live births; trend linesfor 19301958 are based on live births adjusted for underregistration.SOURCE: CDC/NCHS, National Vital Statistics System.

Rateper1,000

womenaged1544

Birthsin

millions

0

40

80

120

160

200

Rate

200820001990198019701960195019401930

0

1

2

3

4

5

Number

Figure2.Livebirthsand fertilityrates:UnitedStates,19302008
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01


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5NationalVitalStatisticsReports,Volume59,Number1,December8,2010

has been generally declining since 1990 (Tables3, 4, 7, and 8;Figure4).From2007to2008,thenumberofbirthstowomeninthisagegroup decreased 3percent, whereas their population increasedslightly.Therate forwomenaged2529alsodeclined in2008,by2percentto115.1birthsper1,000womenfrom117.5in2007.Therateforthisagegroupdeclinedsteadilyfrom1990through1997buthasfluctuated since. The number of births to these women decreased1percent in 2008 from 2007, whereas their population increased1percent.

Womenintheir30sThebirthrateforwomenaged3034was99.3birthsper1,000women in2008,down1percentfromthe2007rate (99.9). The birth rate for women aged 3034 has generallyincreasedsince1976.Birthstowomenaged3034declinedslightlyin2008,whereasthepopulationofthesewomenincreasedslightly.Thebirthrateforwomenaged3539in2008alsowasdown1percent,to46.9birthsper1,000womenfrom47.5in2007.Thismarksthefirstdeclineintherateforthisagegroupinthreedecades;rateshadsteadilyincreased(150percent)from1978to2007.Thenumberofbirthsandthepopulationofwomenaged3539decreased12percent(Tables2and6).

Womenintheir40sThebirthrateforwomenaged4044was9.8livebirthsper1,000womenin2008,3percentabovethe2007rate

(9.5)andthehighestratereportedsince1967(10.6)(Tables4and8)(4).Thebirthrateforthisagegrouphasbeengenerallyincreasingsince1981(3.8)andhasrisen32percentsince1999(7.4)(Figure4).Thenumberofbirths to these women increased 1percent from2007 to2008.Thebirthrateforwomenaged4549alsoincreasedin2008,to0.7birthsper1,000womenfrom0.6in2007.Therateforwomeninthisagegrouphasgenerallyincreasedslowlysince1993(0.3),albeitwith moderate periods of no change. From 2007 to 2008, births towomenaged4549 increased4percent.

Womenaged50andoverThenumberofbirthstowomenaged50 and over was 541 in 2008, 5percent more than in 2007 (514)(Tables2and6).Thenumberofbirthstowomeninthisagegrouphasincreasedmorethan10percentannuallysince1997(144),whendatafor women aged 50 and over became available again. (From 1964through1996,ageofmotherwasimputedifthereportedagewasunder10or50orover;see TechnicalNotes.)

Thebirthrateforwomenaged5054was0.5birthsper10,000women in 2008,unchanged from2007.Becauseofsmallnumbers,birthstowomenaged50andoverhistorically,andforratesshowninalltablesinthisreport,havebeenincludedwithbirthstowomenaged4549whencomputingbirthratesbyageofmother(thedenominator

TableA.Birthrates forwomenaged1019years,byageandbyraceandHispanicoriginofmother:UnitedStates,1991and20052008.[Ratesper1,000women inspecifiedageandraceandHispanicorigingroup]

Year Percent Percent Percentchange, change, change,

Ageand raceandHispanicoriginofmother 2008 2007 2006 2005 1991 20072008 20052007 199120051014years Rate

All racesandorigins1 . . . . . . . . . . . . . . . . . . 0.6 0.6 0.6 0.7 1.4 14 50NonHispanicwhite2 . . . . . . . . . . . . . . . . . . . NonHispanicblack2 . . . . . . . . . . . . . . . . . . . American IndianorAlaskaNative total2,3 . . . . . . .

0.2 1.4 0.9

0.2 1.5 0.9

0.2 1.6 0.9

0.2 1.7 0.9

0.5 4.9 1.6

7

12

6065 44

AsianorPacific Islander total2,3 . . . . . . . . . . . . 0.2 0.2 0.2 0.2 0.8 75Hispanic4. . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 1.2 1.3 1.3 2.4 8 46

1519yearsAll racesandorigins1 . . . . . . . . . . . . . . . . . . 41.5 42.5 41.9 40.5 61.8 2 5 34NonHispanicwhite2 . . . . . . . . . . . . . . . . . . . 26.7 27.2 26.6 25.9 43.4 2 5 40NonHispanicblack2 . . . . . . . . . . . . . . . . . . . 62.8 64.2 63.7 60.9 118.2 2 5 48American IndianorAlaskaNative total2,3 . . . . . . . 58.4 59.3 55.0 52.7 84.1 13 37AsianorPacific Islander total2,3 . . . . . . . . . . . . 16.2 16.9 17.0 17.0 27.3 4 38Hispanic4. . . . . . . . . . . . . . . . . . . . . . . . . . 77.5 81.8 83.0 81.7 104.6 5 221517years:

All racesandorigins1 . . . . . . . . . . . . . . . . . 21.7 22.1 22.0 21.4 38.6 2 3 45NonHispanicwhite2. . . . . . . . . . . . . . . . . . NonHispanicblack2. . . . . . . . . . . . . . . . . . 11.5 34.8 11.8 35.8 11.8 36.2 11.5 34.9 23.686.1 33 33 5159American IndianorAlaskaNative total2,3. . . . . . 32.5 31.8 30.7 30.5 51.9 41AsianorPacific Islander total2,3 . . . . . . . . . . . 7.9 8.2 8.8 8.2 16.3 50Hispanic4 . . . . . . . . . . . . . . . . . . . . . . . . 46.1 47.9 47.9 48.5 69.2 4 1 30

1819years:All racesandorigins1 . . . . . . . . . . . . . . . . . 70.6 73.9 73.0 69.9 94.0 4 6 26NonHispanicwhite2. . . . . . . . . . . . . . . . . . 48.5 50.4 49.3 48.0 70.6 4 5 32NonHispanicblack2. . . . . . . . . . . . . . . . . . 104.6 109.3 108.4 103.0 162.2 4 6 36American IndianorAlaskaNative total2,3. . . . . . 96.6 101.6 93.0 87.6 134.2 5 16 35AsianorPacific Islander total2,3 . . . . . . . . . . . 28.4 29.9 29.5 30.1 42.2 5 29Hispanic4 . . . . . . . . . . . . . . . . . . . . . . . . 127.2 137.2 139.7 134.6 155.5 7 2 13

Differencenotstatisticallysignificant.1Includesbirths towhiteHispanicandblackHispanicwomenandbirthswithoriginnotstated,notshownseparately.2RaceandHispanicoriginarereportedseparatelyonbirthcertificates.PersonsofHispanicoriginmaybeofanyrace.Racecategoriesareconsistentwith1977OfficeofManagementandBudgetstandards. In2008,30statesreportedmultipleracedata thatwerebridged tosingleracecategories forcomparabilitywithotherstates;see TechnicalNotes.Multipleracereportingareasvary for20052008; see TechnicalNotes.3IncludespersonsofHispanicoriginaccording to themothersreportedrace;see TechnicalNotes.4IncludesallpersonsofHispanicoriginofanyrace;see TechnicalNotes.


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fortherateiswomenaged4549years).However,thebirthrateforwomen aged 5054 for 2008 is calculated and reported separatelyhere.Therateisexpressedper10,000womenbecauseofthesmallnumberofbirths.

The increase inbirthrates forwomenaged35andoverduringthe last 20 years has been linked, in part, to the use of fertilityenhancing therapies (15).Live-birthorder

The first-birth rate was 27.7 births per 1,000 women aged1544 in2008,1percentlowerthanin2007(27.9)(Tables3,7,and9).Theratehasgenerallyfluctuatedoverthelast10years.Firstbirthrates for women aged 1529 and 3539 decreased 12percent in2008,whereastherateforwomenaged4044increasedfrom2.0to2.2per1,000theonlyagegrouptoincrease.Firstbirthsforwomeninotheragegroupswereunchanged.

The second through fourthorder birth rates for women aged1544 decreased 2percent each in 2008, whereas rates for fifththrougheighth andhigherorderbirthswereunchanged.

The mean age at first birth, another useful measure in inter pretingchildbearingpatterns,increasedto25.1in2008afterdecliningtoandremainingat25.0in2006and2007(Tables13,14,andInternetTableI1) (4,8,16,17).Themeanisthearithmeticaverageoftheageof mothers at the time of birth and is computed directly from thefrequencyof firstbirthsbyageofmother.The increase in themeanagefrom2007to2008reflects,inpart,therelativelylargedeclineinbirths to women under age 25 compared with the small decline forwomenaged2539.

Average age at first birth varied substantially among race andHispanicorigingroups,rangingfrom21.9yearsforAIANwomento28.7yearsforAPIwomenin2008.Theageoffirsttimemothersforthethreelargest race and Hispanic origin groups was 22.8 years for nonHispanic black, 23.1 years for Hispanic, and 26.0 years for nonHispanic white women.Ageat first birth increased for nonHispanicblackandAPIwomenaswellasMexican,PuertoRican,andCentraland South American women, but it was essentially unchanged fornonHispanicwhiteandCubanwomen (Tables13and14).Total fertilityrate

Thetotalfertilityrate(TFR)estimatesthenumberofbirthsthatahypotheticalgroupof1,000womenwouldhaveovertheirlifetimes,based on agespecific birth rates in a given year.The rate may beexpressedastheaveragenumberofchildrenthatwouldbebornperwoman. Because it is computed from agespecific birth rates, theTFR is ageadjusted and can be compared for populations acrosstime,populationgroups,andgeographicareas.

In 2008, the TFR was 2,084.5 births per 1,000 women, down2percentfrom2007(2,122.0)(Tables4,8,13,and14).TheU.S.ratehadgenerallyincreasedfrom1998through2007.Forthethreelargestrace and Hispanic origin groups, rates decreased 12percent fornonHispanicwhiteandnonHispanicblackwomenin2008from2007,and 3percent for Hispanic women. The TFR for API women alsodecreased1percent,whereas the rate forAIANwomendidnotsig nificantlychangein2008.AmongspecifiedHispanicgroups,therateforMexicanwomendecreased8percent,whereastherateforother

1American Indian or Alaska Native.2Asian or Pacific Islander.SOURCE: CDC/NCHS, National Vital Statistics System.

0

20

40

60

80

100

120

140

2008200720051991

API2AIAN1HispanicNon-Hispanic blackNon-Hispanic white

Rateper1,0

00women

Figure3.Birthrates for teenagersaged1519years,byraceandHispanicorigin:UnitedStates,1991,2005,and20072008
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI01


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Hispanic(CentralandSouthAmericanandunspecifiedHispanicsub groups)womenincreased12percent.(ForinformationonchangesforotherandunknownHispanics,seeTechnicalNotes.)TheTFRsforPuertoRicanandCubanwomendidnotsignificantlychange.

TheU.S.

TFR

was

below

replacement

in

2008,

after

being

above

replacementin2006and2007.Replacementisthelevelatwhichagivengenerationcanexactlyreplaceitself,generallyconsideredtobe2,100birthsper1,000women.Priorto2006,thenationalratehadnotbeenabove replacement for35years.

TFRsdifferwidelybyraceandHispanicoriginand,despite thedeclinesin2008,remainedabovereplacementfornonHispanicblackwomen(2,107.5)andwomeninthefollowingHispanicorigingroups:Mexican (2,866.5), Puerto Rican (2,160.0), and other Hispanic(3,523.0)(Tables4,8,13,and14).Birthsandbirthratesbystate

Amongthe50statesandtheDistrictofColumbia,thenumberofbirths declinedsignificantly in 19states from2007 to2008. Only inWashington did the number of births increase significantly. Thenumber of births in other states and the District of Columbia wereessentially unchanged.Among U.S. territories, the number of birthsdecreased in Puerto Rico and was essentially unchanged inAmericanSamoa,Guam,NorthernMarianas,andVirginIslands;seeTables10and11 for2008data.

Statespecificcrudebirthratesrangedfrom10.2birthsper1,000totalpopulation inVermont to20.3 inUtah in2008 (Table12).Birthratesfell in32states in2008 from2007andwereunchanged in17statesandtheDistrictofColumbia.ThebirthrateincreasedinAlaska

only.AmongU.S.territories,thebirthrateroseinNorthernMarianas,declined in Puerto Rico, and was unchanged in American Samoa,Guam,andVirgin Islands.

In2008,theU.S.fertilityratefell1percent,to68.6birthsper1,000women aged1544.Thisdecline in the fertility rate from2007 wasgeographicallybroadbased,withsignificantdeclinesin19statesrep resenting most regions of the country (Figure5). Fertility ratesincreased in 3 states (Alaska, Hawaii, and Washington) and werestatisticallyunchanged in the remaining28statesand theDistrictofColumbia.Statespecific2008fertilityratesrangedfrom52.4birthsper1,000womenaged1544inVermontto93.1inUtah(Table12).AmongU.S. territories,thefertilityratedeclined inPuertoRico, increased inNorthernMarianas,andwasunchangedinVirginIslands,Guam,andAmericanSamoa.

TFRs,whichprovideasummaryoflifetimefertility,rangedin2008from1,673.0per1,000(1.7birthsperwoman)inVermontto2,597.0(2.6birthsperwoman)inUtah(Table12).DifferencesinTFRsamongstatesandchangesin2008from2007forindividualstatesaresimilarto thosenoted forGFRs.Birthratesfor teenagersbystate

In 2008, the U.S. birth rate for teenagers aged 1519 fell2percentto41.5per1,000.Thedeclineinthenationalteenagebirthratein2008from2007wasdrivenbysignificantdeclinesin14states(Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana,Maryland, Massachusetts, Michigan, Minnesota, Mississippi, NewYork,andVirginia), representing manydifferentparts of the country(TableB). Only Montana reported a significant increase in the teenbirthrate (18).

In2008,teenagebirthratesrangedfrom19.8inNewHampshireto65.7inMississippi(TableBand12).Thewiderangeinstatespecificteen rates isconsistentwithpatternsobserved inpreviousyears. In2008, as in previous years, teenage birth rates were lowest in theNortheast and upper Midwest and highest across the South andSouthwest(18).ContributingtothevariationinstatespecificteenbirthratesarepersistentdifferencesinteenagebirthratesamongraceandHispanicorigingroups;seeearliersectiononAgeofmother.Nation ally,birthratesaresignificantlyhigherforHispanicandnonHispanicblackteenagersthanfornonHispanicwhiteteenagers.ItfollowsthatstateswithalargeproportionofHispanicornonHispanicblackteen agerswouldtendtohavehigheroverallteenbirthrates.WidelyvaryingstatespecificbirthratesforHispanicandnonHispanicblackteenagershavecontributedtosomenotableexceptionstothispattern,however,asillustratedinarecentanalysisofstatespecificteenagebirthrates(18).Forexample,Californiasteenbirthrateissignificantlylowerthanthenational ratedespite its largeproportionofHispanic teens.Births tounmarriedwomen

The number of births to unmarried women rose to 1,726,566,about 1percent more than in 2007. The 2008 total was again arecordhighforthenation.From2002through2007,nonmaritalbirthsrose 26percent; the increase from 2007 to 2008 was the smallestsince 20012002 (TableC). The birth rate for unmarried women,which relates nonmarital births to unmarried women in the child bearing ages, rose slightly in 2008 from 2007, from 52.3 to 52.5birthsper1,000unmarriedwomenaged1544.During theprevious

Rateper1,0

00wome

n

3539 years

2024 years

2529 years

3034 years

4044 years

1519 years

NOTE: Rates are plotted on a logarithmic scale.SOURCE: CDC/NCHS, National Vital Statistics System.

1990 1995 2000 2005 20081

5

10

50

5

50

100

200 200

1

10

100

Figure4.Birthrates,byselectedageofmother:UnitedStates,19902008


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5year period (20022007), the rate rose by 20percent overall orabout 4percent per year (TablesC, 15, and 16). A third summarymeasureofnonmaritalchildbearing is thepercentageofallbirths tounmarriedwomen.Thismeasurerose in2008at thesamepaceasduring20022007,to40.6percentin2008.Thepercentagehasbeenincreasingbyanaverageof3percentperyearsince2002.Measuresof nonmarital births had been relatively stable during 19982002(TableC). Contributing to the recent upturn in nonmarital births aretheongoingincreases inthebirthrateforunmarriedwomenandthegrowth in the population of unmarried women of childbearing age(19).

Theslightincreaseinthebirthrateforunmarriedwomenreflectsentirelytheincreasesinratesforwomeninagegroupsof30andover(Table16).Ratesdeclined forallwomenunder30,whoaccount formorethan80percentofallnonmaritalbirths.Thedeclineforwomenintheirearly20swasthefirstsince20012002.Ratesforwomenaged30 and over rose by 39 to 46percent from 2002 through 2008(Table16).Nearlyoneinfivenonmaritalbirthsin2008weretowomenaged30andover,doubletheproportionin1980(9percent)(Table15for2008data)(20,21).

Nonmarital birth rates by race and Hispanic origin generallychangedlittlebetween2007and2008.TheratefornonHispanicwhitewomen(33.7per1,000)rose1percent,andtherateforblackwomen(72.5) was essentially unchanged. The rate for Hispanic womendeclined 3percent to 105.1. The rate forAPI women was 28.2 per1,000.Trendsbymaternalagesince2002weresimilaracrosspopu lationgroups(Table16).

In2008,40.6percentofallbirthsweretounmarriedwomen,upfrom 39.7percent in 2007 and 34.0percent in 2002 (TableC).

Majoritiesofbirthstoteenagers(87percent)andtowomenintheirearly20s(61percent)werenonmarital in2008 (Tables2and15).Twentypercentofbirths towomenaged30andoverwerenonmarital.Theproportions of nonmarital births vary widely among population sub groups:17percentforAPI,29percentfornonHispanicwhite,53per centforHispanic,66percentforAIAN,and72percentfornonHispanicblackbirths in2008.

Proportionsofnonmaritalbirthsvaryconsiderablyacrossstates.In2008,theproportionsbystatewerelowestinUtah,Colorado,andIdaho(ranging from20 to25percent),whileat leasthalfofbirths intheDistrictofColumbia,Mississippi,NewMexico,andLouisianaweretounmarriedwomen(InternetTableI4).Thesevariationsinlargepartreflect differences in race and Hispanic origin composition amongstates.Ageoffather

Thebirthrateper1,000menaged1554was49.4in2008,a2percentdecline from the2007rate(50.3)(Table17).Byage,birthratesfellorwerestatisticallyunchangedin2008from2007formalesofallagegroupsexceptteensaged1519.Birthratesforteenagersincreased2percentin2008to19.0from18.7in2007.Birthratesformenaged2024(73.1)and2529(102.2)felltoalltimelows.Ratesformenaged3034(105.2)and3539(63.6)alsodeclinedin2008.Formenaged40orover,rateswereessentiallyunchanged.

Byrace,birthrateswerehigherforblackmen(64.4)thanforwhitemen(46.8)in2008,asinpreviousyears.Muchofthedifferencecanbeattributedtohigherratesforblackmenunderage30;ratesarequitesimilar forblackandwhitemenaged3039.

SOURCE: CDC/NCHS, National Vital Statistics System.

AK

HI

DC

RI

NJ

DE

MD

MA

MS

LA

UT

CA

AZNM

TX

GA

FL

ID

OR

MT

SD

ND

SC

NV

AL

IA

MN

WI

ME

CT

NE

VA

OH

PA

IL

MI

WA

KSCO

IN

KY

WV

NCTN

VT

AROK

NY

MO

WY

NH

Increased significantly

No significant difference

Decreased significantly

Ten largest significant declines

U.S. fertility ratewas 69.5 in 2007and 68.6 in 2008.

Figure5.Change infertilityrates:UnitedStates,2007and2008
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI04


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Informationonageoffatherisoftenmissingonbirthcertificatesofchildrenborntowomenunderage25andtounmarriedwomen.In2008, age of father was not reported for 14percent of all births,24percentofbirthstoallwomenunderage25,and33percentofallnonmaritalbirths.Theproceduresforcomputingbirthratesbyageoffatheraredescribed in theUserGuide (9).MaternalLifestyleandHealthCharacteristicsMedicalservicesutilizationAttendantatbirthandplaceofdelivery

In2008,99.0percentofallbirthsweredeliveredinhospitals.Ofall2008births,91.3percentweredeliveredbyphysiciansinhospitals(Table20).Almostallofphysicianattendedbirths(94.4percent)wereattendedbydoctorsofmedicine (M.D.s) in2008.

OnepercentofallbirthsintheUnitedStateswereoutofhospitalbirths in2008.Of the42,746outofhospitalbirths,nearly twothirdswereinaresidence(home)(66.3percent)and28.1percentwereinafreestanding birthing center (Table20). In 2008, midwives attended

61.2percentofhomebirths.Morethan80percentofhomebirthsweretononHispanicwhitewomen.

In2008, ratesofhomebirthweregreater than1percent in16states, most of which were in the western United States (data notshown). Montana (2.2percent) and Vermont (2.0percent) had thehighestratesofhomebirthsin2008.Twentyonestateshadahomebirthrateequaltoorlessthan0.5percent.Arecentstudyof19statesbasedonrevisedbirthcertificatedatashowedthatmorethan80per centofhomebirthswereplannedhomebirths(22).Homebirthsaremuchmorecommoninruralcounties(populationoflessthan100,000)than incountieswith largerpopulations(23).

The2008percentageofallbirthsattendedbymidwiveswas8.0,very little changed since 2004. For 2008, certified nurse midwives(CNMs)delivered93.9percentofallmidwifeattendedbirths.Thisratehas remained at 90percent or more since 1989. Over 9 out of 10midwifeattendedbirthsoccurred inhospitals (91.7percent in2008).CNMattendedhospitalbirthsaremorethantwiceasfrequentamongAIANwomen(16.9percent)asamongHispanicwomen(8.1percent),nonHispanic white (7.0percent), and nonHispanic black women(6.8percent).RateswerelowestforAPIwomen(5.9percent)(datanotshown).SeeTables18and19 for totalCNMattendedbirthsamongAIAN,API,andHispanicsubgroups.

TableB.Birthrates for teenagersaged1519years,bystate:UnitedStatesandeachstateand territory,1991,2005,2007,and2008[Birth ratesper1,000estimated femalepopulationaged1519 ineacharea]

Percent Percent Percent Percent Percent Percentchange, change, change, change, change, change,2007 2005 1991 2007 2005 1991

Area 2008 2007 2005 1991 2008 2007 2005 Area 2008 2007 2005 1991 2008 2007 2005UnitedStates1 . . . . . . . . 41.5 42.5 40.5 61.8 2 5 34 Nebraska . . . . . . . . . . . 36.5 36.1 34.2 42.4 19Nevada . . . . . . . . . . . . 53.5 55.3 50.1 74.5 10 33Alabama. . . . . . . . . . . . 53.0 54.1 49.7 73.6 9 32 NewHampshire . . . . . . . 19.8 20.0 17.9 33.1 12 46Alaska. . . . . . . . . . . . . 46.8 44.7 37.3 66.0 20 43 NewJersey. . . . . . . . . . 24.5 25.2 23.4 41.3 8 43Arizona . . . . . . . . . . . . 56.2 61.2 58.2 79.7 8 5 27 NewMexico. . . . . . . . . . 64.1 66.1 61.6 79.5 7 23Arkansas . . . . . . . . . . . 61.8 61.7 59.1 79.5 4 26 New York . . . . . . . . . . . 25.2 25.8 26.5 45.5 2 3 42California . . . . . . . . . . . 38.4 39.7 38.8 73.8 3 2 47 NorthCarolina . . . . . . . . 49.4 49.9 48.5 70.0 3 31Colorado. . . . . . . . . . . . 42.5 43.4 42.6 58.3 27 NorthDakota . . . . . . . . . 28.6 29.3 29.7 35.5 16Connecticut . . . . . . . . . . 22.9 23.1 23.3 40.1 42 Ohio . . . . . . . . . . . . . . 41.0 41.3 38.9 60.5 6 36Delaware . . . . . . . . . . . 40.4 40.6 44.0 60.4 8 27 Oklahoma. . . . . . . . . . . 61.6 61.5 54.2 72.1 13 25DistrictofColumbia . . . . . 50.9 49.9 63.4 109.6 21 42 Oregon. . . . . . . . . . . . . 37.2 35.9 33.0 54.8 9 40Florida. . . . . . . . . . . . . 42.8 45.5 42.4 67.9 6 7 38 Pennsylvania . . . . . . . . . 31.5 31.5 30.4 46.7 4 35Georgia . . . . . . . . . . . . Hawaii. . . . . . . . . . . . . 51.842.1 54.941.3 52.736.2 76.059.2 6 414 3139 Rhode Island . . . . . . . . . SouthCarolina . . . . . . . . 28.553.1 30.053.6 31.451.0 44.772.5

5 3030

Idaho. . . . . . . . . . . . . . 41.2 41.4 37.7 53.9 10 30 SouthDakota. . . . . . . . . 40.0 42.2 37.5 47.6 13 21Illinois . . . . . . . . . . . . . 38.1 40.0 38.6 64.5 5 4 40 Tennessee. . . . . . . . . . . 55.6 56.2 54.9 74.8 27Indiana. . . . . . . . . . . . . 43.7 45.2 43.2 60.4 3 5 28 Texas. . . . . . . . . . . . . . 63.4 64.2 61.6 78.4 4 21Iowa . . . . . . . . . . . . . . 33.9 33.2 32.6 42.5 23 Utah . . . . . . . . . . . . . . 35.1 36.1 33.4 48.0 8 30Kansas. . . . . . . . . . . . . 45.6 43.7 41.4 55.4 6 25 Vermont . . . . . . . . . . . . 21.3 22.0 18.6 39.2 18 53Kentucky. . . . . . . . . . . . 55.6 55.1 49.1 68.8 12 29 Virginia. . . . . . . . . . . . . 33.5 35.1 34.4 53.4 5 36Louisiana . . . . . . . . . . . 54.1 55.9 49.1 76.0 3 14 35 Washington . . . . . . . . . . 34.6 34.8 31.1 53.7 12 42Maine . . . . . . . . . . . . . 26.1 26.9 24.4 43.5 10 44 WestVirginia . . . . . . . . . 48.8 47.4 43.4 58.0 9 25Maryland. . . . . . . . . . . . 32.8 34.4 31.8 54.1 5 8 41 Wisconsin. . . . . . . . . . . 31.3 32.2 30.3 43.7 6 31Massachusetts . . . . . . . . 20.1 22.1 21.8 37.5 9 42 Wyoming . . . . . . . . . . . 49.2 51.9 43.2 54.3 20 20Michigan. . . . . . . . . . . . 33.2 34.2 32.5 58.9 3 5 45Minnesota. . . . . . . . . . . 27.2 28.6 26.1 37.3 5 10 30 PuertoRico. . . . . . . . . . 54.9 57.1 61.2 72.4 4 7 15Mississippi. . . . . . . . . . . 65.7 71.9 60.5 85.3 9 19 29 Virgin Islands. . . . . . . . . 51.1 51.5 50.0 77.9 36Missouri . . . . . . . . . . . . 45.5 45.7 42.5 64.4 8 34 Guam . . . . . . . . . . . . . 55.0 60.0 59.2 95.7 38Montana. . . . . . . . . . . . 40.7 36.8 35.2 46.8 11 25 AmericanSamoa. . . . . . . 37.1 28.9 34.2 Differencenotstatisticallysignificant. Datanotavailable.1Excludesdata for the territories.NOTE:Populationdata forcomputingbirthrateswereprovidedby theU.S.CensusBureau.Ratesbystatemaydiffer fromratescomputedon thebasisofotherpopulationestimates.


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MethodofdeliveryThetotalcesareandeliveryrateincreasedin2008forthe12th

consecutive year, reaching 32.3percent (Table21). This is nearly a2percent increase from 31.8percent in 2007, and a 56percentincrease from the most recent low of 20.7 in 1996 (8).The rate ofincrease for the total cesarean delivery rate continues to slow,however,sincetheunprecedented7percentrise in2002from2001;by comparison, the rate of increase was 2.3percent in 2007 from2006and1.6percent in2008 from2007(8).DatafromtheNationalHospital Discharge Survey showsimilar trends in cesareandeliverysince themid1990s (24,25).

Cesareandeliveryrates forallmaternalagegroups rose in2008 from 2007 (see Table22 for 2008 data). Rates for most agegroupsincreased12percent.Birthstoolderwomenweremorelikelytobedeliveredbycesarean;ratesforwomenaged40to54(49.0per cent)weretwiceashighasratesforwomenunderage20(23.0per cent).Thisisalsothecaseamongsingletonbirths(womenaged4054are more likely to have multiple births, which are at higher risk forcesareandelivery).

Cesareandeliveryratesforthelargestraceandethnicgroupsincreased12percentin2008from2007(seeTable22for2008data).NonHispanic black womenweremore likely to deliver by cesarean(34.5percent) than nonHispanic white (32.4percent) and Hispanic(31.0percent)women.CesareandeliveryrateshavebeenhigherfornonHispanicblackwomensince1994,thereasonsforwhichremainunclear (26)(Table21andFigure6).

As with the overall rate, cesarean delivery rates by race andHispanicoriginandageofmotherareincreasingataslowerpacethaninrecentyears.Figure6showsthesteadyriseincesareanbirthsfromthemid tolate1990sthrough2004,followedbythedecliningpaceof

increase from 2005 through 2008. More detail on recent trends incesareandeliveryfrom1996through2007isavailableinarecentreport(27).

Thecesareanratehasalsoslowedinrecentyearsinmanystates.In2008,22 stateshad higher cesareandelivery rates than in2007(2.5percentaverage increase). In2007, rates for28statesand theDistrictofColumbiaincreasedfrom2006byanaverageof3.3percent,andratesin37statesroseanaverageof3.8percentfrom2005.Ratescontinuedtovarygreatlybystatein2008,rangingfrom22.0percentin Utah to 38.7percent in New Jersey. See Internet TableI7 forstatespecificcesareandeliveryrates for2008.

Therise inthetotalcesareandeliveryratesincethemid1990shas been driven by increases in primary cesarean deliveries anddecreasesinvaginalbirthsaftercesareandelivery(VBAC)(24,28).TheincreaseinprimarycesareansanddeclineinVBACsmayhavebeeninfluenced by shifts in demographics, maternal choice, and othernonclinical factors, as well as VBAC guidelines from the AmericanCollege of Obstetricians and Gynecologists (ACOG) and increasedmedicolegalpressure(2932).InformationonprimarycesareanandVBACforthe27revisedstatereportingareawillbepresented inanupcomingreport.

Births delivered by either forceps or vacuum extractiondecreasedagain in2008,to3.9percentofbirthsfrom4.3percent in2007 (TableD).Deliverywith forcepsdecreased to0.7percent from0.8percentin2007;vacuumextractiondecreasedto3.2percentfrom3.5

percent.

There

has

been

adecline

in

these

procedures

for

the

past

twodecades;in1990,nearly1in10birthsweredeliveredwitheitherforcepsorvacuumcomparedwith less than1 in25 in2008.

InfantHealthCharacteristicsPeriodofgestation

Thepretermbirthratedeclinedin2008forthesecondyearinarowto12.3percent,3percentlowerthanthe2007rate(12.7percent)and 4percent lower than in 2006 (12.8percent) (TablesE, 23, and24).Thepretermbirthrate(birthatlessthan37completedweeksof

TableC.Birthsandbirthrates forunmarriedandmarriedwomen:UnitedStates,1980,1985,and19902008

Year2008 . . . . . . . . . . . . . . . . . . . . . 1,726,566 52.5 40.6 86.82007 . . . . . . . . . . . . . . . . . . . . .

1,715,047

52.3

39.7

88.72006 . . . . . . . . . . . . . . . . . . . . . 1,641,946 50.6 38.5 88.0

2005 . . . . . . . . . . . . . . . . . . . . . 1,527,034 47.5 36.9 87.32004 . . . . . . . . . . . . . . . . . . . . . 1,470,189 46.1 35.8 87.62003 . . . . . . . . . . . . . . . . . . . . . 1,415,995 44.9 34.6 88.12002 . . . . . . . . . . . . . . . . . . . . . 1,365,966 43.7 34.0 86.32001 . . . . . . . . . . . . . . . . . . . . . 1,349,249 43.8 33.5 86.72000 . . . . . . . . . . . . . . . . . . . . . 1,347,043 44.1 33.2 87.41999 . . . . . . . . . . . . . . . . . . . . . 1,308,560 43.3 33.0 84.81998 . . . . . . . . . . . . . . . . . . . . . 1,293,567 43.3 32.8 84.21997 . . . . . . . . . . . . . . . . . . . . . 1,257,444 42.9 32.4 82.71996 . . . . . . . . . . . . . . . . . . . . . 1,260,306 43.8 32.4 82.31995 . . . . . . . . . . . . . . . . . . . . . 1,253,976 44.3 32.2 82.61994 . . . . . . . . . . . . . . . . . . . . . 1,289,592 46.2 32.6 82.91993 . . . . . . . . . . . . . . . . . . . . . 1,240,172 44.8 31.0 86.11992 . . . . . . . . . . . . . . . . . . . . . 1,224,876 44.9 30.1 88.51991 . . . . . . . . . . . . . . . . . . . . . 1,213,769 45.0 29.5 89.61990 . . . . . . . . . . . . . . . . . . . . . 1,165,384 43.8 28.0 93.21985 . . . . . . . . . . . . . . . . . . . . . 828,174 32.8 22.0 93.31980 . . . . . . . . . . . . . . . . . . . . . 665,747 29.4 18.4 97.0

Births tounmarriedwomenBirthrate for

Number Rate1 Percent2 marriedwomen3

1Births tounmarriedwomenper1,000unmarriedwomenaged1544years.2Percentageofallbirths tounmarriedwomen.3Births tomarriedwomenper1,000marriedwomenaged1544.

SOURCE: CDC/NCHS, National Vital Statistics System.

Pe

rcent

0

20

25

30

35

Hispanic

Non-Hispanic white

Non-Hispanic black

20082005200019951993

Figure6.Cesareandelivery,byraceandHispanicoriginofmother:UnitedStates,19932008
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI07


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NationalVitalStatisticsReports,Volume59,Number1,December8,2010 11

gestationper100 totalbirths) rosemore than20percent from1990through 2006. Declines in 2008 from 2007 were observed amongboth early (less than 34 weeks) and late (3436 weeks) pretermbirths;seeTableE.From1990 through2006, theearlypretermratehad increased modestly (from 3.32percent), whereas the late preterm rate rose 25percent (from 7.3percent) (33,34). See the UserGuide

for

information

on

gestational

age

measurement

(9).

Theriskofpoorbirthoutcomegenerallydeclineswithadvancing

gestationalage.Althoughriskisgreatestamongbabiesbornbeforethe34thweek,infantsbornlatepretermaremorelikelytosufferdeliverycomplications, longterm impairment,andearlydeathcomparedwiththoseborn later inpregnancy(3537).

Pretermbirthratesdeclined34percentfrom2007to2008amongnonHispanicwhite(to11.1from11.5percent)andnonHispanicblackinfants (to 17.5 from 18.3percent), and 2percent among Hispanicbirths(to12.1from12.3percent)(Table24).From1990through2006,pretermrateshadrisen38percentfornonHispanicwhiteinfantsand

11percent for Hispanic infants. Among nonHispanic black infants,pretermbirthratestrendedslightlydownwardfrom1990through2000(down8percent),butrose6percentfrom2000through2006.The2008nonHispanicblackpretermrate is the lowestreportedsince2000.

Thesingletonpretermbirthratealsodeclined for thesecondstraight year, to 10.6percent in 2008 from 11.0percent in 2007.Asmallerdeclineinthisratewasreportedin2007from2006(11.1per cent) (TableE). It is often helpful to examine preterm rates amongsingletonbirthsonlybecauseofthesubstantialimpactofmultiplebirthson the overall preterm birth rate. (See Multiple births section forinformationonthegreaterlikelihoodofpretermbirthamongmultiplesand recentchanges inmultiplebirth rates.)Trends inearlyand latepretermsingletonbirthsfor2007and2008weresimilartothoseofallbirths,thatis,significantdeclineswerenotedinthepercentageofbothearly(from2.95to2.87percent)andlate(from8.03to7.76percent)pretermsingletons.

Mothersunderage15andaged45andoveraremost likelytohaveapretermdelivery(Table25).Ratesfortheyoungestandoldestmothersareabout twice thoseofmothersaged2534.Thepretermratesforolderwomenarestronglyinfluencedbytheirgreaterlikelihoodof having a multiple birth; when singletons births are examined forwomenaged45andover,thepretermbirthratedropsfrom27.1per cent to16.7percent(datanotshown).

By state, preterm birth rates ranged from under 10percent inIdaho,NewHampshire,andVermontto18percentofMississippibirths.Arecentreportshowssignificantdeclinesinpretermbirthratesfor35statesin2008from2006(34).StatespecificratesbyraceandHispanicoriginareshown in InternetTableI8.

Termbirths(3741weeks)havetraditionallybeenviewedasahomogenous group (8). There is, however, growing evidence ofincreasedneonatalmorbidityamongearlyterm(3738weeks)infantscompared with those born full term (3941 weeks) (3739). Inresponse, organizations such as the March of Dimes are recom mending that researchers differentiate between early and fulltermbirths(40).Thisreportfollowsthisrecommendationandpresents,forthefirsttime,abriefdiscussionoftrendsinearlyandfulltermbirths.TablesEand23havealsobeenrevisedtodifferentiatebetweenearlyand fulltermbirths.

The percentage of early term births (3738 weeks) declined3percent in 2008 from 2007, to 27.8 from 28.6percent. A smallerdeclineinearlyterminfantswasalsoobservedin2007from2006(to28.6 from28.9percent);seeTableEandFigure7.Therateofearlytermbirthshadincreasednearly50percentfrom1990(19.7percent)through2006(28.9percent).Overthemorerecent20062008period,concurrentwiththedeclineinbirthsdeliveredpretermandearlyterm,the percentage of infants delivered at full term rose from 52.6 to54.1percent(Figure7).

Theriseinpretermandearlytermbirthsduring19902006mayberelated,at least inpart,tochanges inhow laboranddeliveryaremanaged,thatis,morefrequentuseofinductionoflaborandcesareandeliverypriorto39weeks(37,4042).Recenteffortstoreduceelec tivedeliveriesatlessthanfulltermmayhavecontributedtothemorerecentdecline(43,44).Birthweight

The lowbirthweight(LBW)ratedeclinedby less than1percentin 2008 to 8.18percent of births from 8.22percent in 2007. This

TableD.Livebirthsdeliveredby forcepsorvacuumextraction:UnitedStates,1990,1995,2000,2005,2007and2008

Vacuum ForcepsorYear Forceps extraction vacuum

Percent2008 . . . . . . . . . . . . . . . . . . . . . 0.7 3.2 3.9 2007 . . . . . . . . . . . . . . . . . . . . .

0.8

3.5

4.3

2005 . . . . . . . . . . . . . . . . . . . . . 0.9 3.9 4.8 2000 . . . . . . . . . . . . . . . . . . . . . 2.1 4.9 7.0 1995 . . . . . . . . . . . . . . . . . . . . . 3.5 5.9 9.4 19901 . . . . . . . . . . . . . . . . . . . . . 5.1 3.9 9.0 1Excludesdata forOklahoma,whichdidnot requirereportingofmethodofdelivery.

TableE.Percentdistributionofbirths,bygestationalageforallbirthsandsingletonbirths:UnitedStates,1990,2000,and20052008

AllbirthsGestationalage 2008 2007 2006 2005 2000 1990

PercentUnder28weeks . . . . . . . 0.74 0.77 0.76 0.77 0.72 0.712831weeks . . . . . . . . . 1.24 1.27 1.29 1.26 1.21 1.213233weeks . . . . . . . . . 1.57 1.60 1.62 1.60 1.49 1.40

Totalunder34weeks. . . 3.56 3.64 3.66 3.63 3.42 3.323436weeks . . . . . . . . . 8.77 9.04 9.15 9.09 8.22 7.30

Totalunder37weeks. . . 12.33 12.68 12.80 12.73 11.64 10.623738weeks . . . . . . . . . 27.85 28.60 28.89 28.29 24.50 19.6639weeks . . . . . . . . . . . 26.62 25.85 25.43 25.25 24.32 21.724041weeks . . . . . . . . . 27.52 27.24 27.20 27.90 32.26 36.6842andmoreweeks. . . . . 5.68 5.62 5.67 5.84 7.28 11.33

SingletonsPercent

Under28weeks . . . . . . . 0.60 0.62 0.61 0.61 0.59 0.612831weeks . . . . . . . . . 1.00 1.03 1.04 1.02 0.99 1.083233weeks . . . . . . . . . 1.27 1.29 1.31 1.28 1.22 1.24

Totalunder34weeks. . . 2.87 2.95 2.96 2.91 2.80 2.933436weeks . . . . . . . . . 7.76 8.03 8.14 8.09 7.33 6.77

Totalunder37weeks. . . 10.63 10.98 11.09 11.00 10.12 9.703738weeks . . . . . . . . . 27.79 28.59 28.91 28.30 24.38 19.4339weeks . . . . . . . . . . . 27.38 26.59 26.15 25.96 24.89 21.984041weeks . . . . . . . . . 28.37 28.07 28.03 28.75 33.15 37.3542andmoreweeks. . . . . 5.83 5.77 5.83 5.99 7.46 11.53
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI08


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changefollowsasmalldecline inLBW in2007from2006(8.26per cent) (Tables2325).ThepercentageofLBW infants,or thosebornat less than 2,500 grams (5 lb. 8 oz.), rose 24percent from 1984through 2006. The decline in LBW in 2008 from 2007 was amongverylowbirthweight(VLBW)infants(lessthan1,500grams),to1.46from1.49percent; thepercentageof infantsbornatmoderately lowbirthweight (MLBW), or 1,5002,499 grams, was unchanged at6.73percent.(ThedeclineinLBWin2007from2006wasexclusivelyamongMLBW infants [8].)

Infant sizeatbirth isan importantpredictor ofshorttermcom plications and longterm health (45,46). Smaller infants, especiallythosebornatlessthan1,500grams,areatthegreatestrisk.In2006,forexample,24percentofVLBW infantsdied in the firstyearof lifecomparedwith0.2percentofinfantsbornat2,500gramsandhigher(35).

LBWratesdeclinedfrom2007to2008amongnonHispanicwhite(7.2percent from 7.3percent) and nonHispanic black infants(13.7percent from 13.9percent); nonstatistically significant declineswereobservedforthepreviousperiod(2007comparedwith2006)forbothgroups(Table24).LevelsofLBWamongHispanicbirths(7.0per cent in 2008) have been essentially stable since 2006. From 1990through2006,nonHispanicwhiteLBWratesclimbed30percent(from5.6to7.3percent),andHispanicLBWratesby15percent(from6.1to7.0percent).LBWamongnonHispanicblackinfantstrendedslightlydownwardduringthe1990sbutrose7percentfrom2001through2006(from13.1 to14.0percent).

Levels of VLBW were not significantly changed among nonHispanicwhiteandHispanic infants in2008 from2007butdeclined

notably among nonHispanic black infants, to 3.01percent from3.20percent, the lowest level reported in more than a decade(Table24).RatesofVLBWhadbeenslowlyontheriseforallgroupssinceatleast1990.SeeTables18and19forVLBWandLBWratesforAIAN,API,andHispanicsubgroups.

TheLBWrateforsingletonbirthsalsodeclinedslightly in2008,to6.40percent.This ratewasalsodownslightly in2007 from2006(6.45percent from 6.49percent).The singleton LBW rate had risen10percentfrom1990through2006,comparedwithariseof19percentamong all births (TableF). Over the past several decades, nationalLBWlevelshavebeeninfluencedbythegrowthintherateofmultiplebirths,asinfantsborninmultipledeliveriesaremuchmorelikelytobeof LBW than those born in single deliveries; see Multiple birthssection.

Concomitantwiththesmalldeclineininfantsdeliveredatlessthan2,500 grams, the percentage of infants born at 2,5003,499 gramsincreasedslightlyin2008from2006(57.8percentfrom57.3percent).Levelsat3,500gramsandhighercontinuedtodecline;seeTableG.During 19902006, a large shift in the birthweight distribution wasobserved.Inbrief,birthsatlessthan3,500gramsincreased,whereasbirthsathigherweightsdecreased.Thereasons for theshift towardlower birthweights are not fully understood, but due to the strongassociation between birthweight and gestational age, they may besimilar to those suggested for the shift toward shorter gestationalagesthatis,obstetricinterventionearlierinpregnancyandchangingmaternaldemographicsandmedicalriskprofiles(42,4749).

LBW incidencedifferedwidelybystate in2008,as inpreviousyears. In2008, levels ranged from6.0percentofbirths inAlaska to

NOTE: Early term is 3738 completed weeks of gestation, and full term is 3941 weeks.SOURCE: CDC/NCHS, National Vital Statistics System.

4041 weeks39 weeks

Full termEarly term

3738 weeks

Percent

20082007200620001990

0

20

25

30

35

40

45

Figure7.Distributionofearly- and full-termbirths:UnitedStates,1990,2000,and20062008


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NationalVitalStatisticsReports,Volume59,Number1,December8,2010 1311.8percentofbirthsinMississippi.InternetTablesI9andI10showLBWandVLBWratesbystate,territory,andraceandHispanicorigin.Multiplebirths

The twin birth rate rose 1percent in 2008, to 32.6 twins per1,000birthsfrom32.2in2007.Thetwinningrateclimbed70percentfrom1980through2004(from18.9to32.2)butwasessentiallystablefrom 2004 through 2007 (Tables26 and 27). There were 138,660infantsbornintwindeliveriesin2008,onlyslightlyfewerthanin2007(138,961).

The2008tripletandhigher-ordermultiple(triplet/+)birthratewas147.6per100,000births,notstatisticallylowerthanthe2007rate(148.9)(Tables26and27).Thetriplet/+birthrate(numberoftriplets,quadruplets, and quintuplets and other higherorder multiples per100,000 births) rose more than 400percent during the 1980s and1990s before peaking in 1998 at 193.5. Since 1998, however, thetriplet/+ rate has trended downward, with the bulk of the declineoccurringsince2003;the2008ratewas24percentlowerthanthatfor1998(Figure1).

There

were

6,268

triplet/+

births

in

2008,

the

lowest

number

reportedinmorethanadecade.The2008triplet/+totalincluded5,877triplets,345quadruplets,and46quintupletsandhigherordermultiples.

Theriskofadverseshort andlongtermbirthoutcomeincreaseswiththenumberofinfantsinamultigestationpregnancy.Forexample,in2008,1percentofsingletonscomparedwith10percentoftwinsand36percentof tripletswerebornat less than1,500grams,or3 lb.4oz. (TableH). Infantsborn inmultipledeliveriesaremore likely thansingletons todie in infancy(35)or tosuffer lifelongmorbidities(50).

Inthelate1990s,inanefforttoreducetheincidenceofhigherorder,multiplegestationpregnancies,theAmericanSocietyofRepro ductiveMedicinepublishedguidelines(subsequentlyupdated)onthenumberofembryostobetransferredininvitrofertilization(IVF)cycles(5153).Recentresearchsuggeststhatthenumberofembryostrans ferredhassincedeclined(54,55).Theearlierlargeandextendedrisein multiplebirth rates during the 1980s and 1990s, particularly theincidence of triplet/+ births, has been associated with two relatedtrends, older age at childbearing and the growing use of fertilityenhancing therapies (56,57).

Alloftheincreaseintheoveralltwinbirthratein2008from2007wasamongbirthstowomenaged30andover;rateswereup2percentforwomenintheir30sand7percentforwomenaged40andover.In2008,6percentofallbirthstowomenaged4044and22percentofbirthstowomenaged45andoverwasatwin,comparedwithlessthan2percentofbirths to teenagedmothers (Table26).

In2008, the twinning rate rose from2007amongnonHispanicwhitewomen(36.6from36.2per1,000)butwasessentiallyunchangedfornonHispanicblack(36.8)andHispanicwomen(22.3)(Table27).Since1990,rateshaverisen60percentfornonHispanicwhitewomencomparedwithrisesof38percentfornonHispanicblackand24per cent forHispanicwomen.

No significant changes in triplet/+ birth rates were observed in2008 from 2007 among the three race and Hispanic origin groups:nonHispanicwhite(198.1per100,000),nonHispanicblack(91.3),andHispanic women (80.1) (Table27). National trends in triplet/+ birthslargelyreflecttrendsintriplet/+birthstononHispanicwhitemothers,whichhave longcomprised thebulkofall triplet/+births (72percentofalltripletbirthsin2008).From1990through1998,thetriplet/+rate

TableF.Percentageofsingletonbirthsofvery lowandlowbirthweight,byraceandHispanicoriginofmother:UnitedStates,1990,1995,2000,and20052008

Very low LowYear birthweight1 birthweight2

All races32008 . . . . . . . . . . . . . . . . . . . . . 1.11 6.402007 . . . . . . . . . . . . . . . . . . . . .

1.14

6.452006 . . . . . . . . . . . . . . . . . . . . . 1.14 6.49

2005 . . . . . . . . . . . . . . . . . . . . . 1.14 6.412000 . . . . . . . . . . . . . . . . . . . . . 1.11 6.001995 . . . . . . . . . . . . . . . . . . . . . 1.08 6.051990 . . . . . . . . . . . . . . . . . . . . . 1.05 5.90NonHispanicwhite42008 . . . . . . . . . . . . . . . . . . . . . 0.82 5.262007 . . . . . . . . . . . . . . . . . . . . . 0.83 5.322006 . . . . . . . . . . . . . . . . . . . . . 0.85 5.372005 . . . . . . . . . . . . . . . . . . . . . 0.84 5.322000 . . . . . . . . . . . . . . . . . . . . . 0.80 4.881995 . . . . . . . . . . . . . . . . . . . . . 0.78 4.871990 . . . . . . . . . . . . . . . . . . . . . 0.73 4.56NonHispanicblack42008 . . . . . . . . . . . . . . . . . . . . . 2.49 11.602007 . . . . . . . . . . . . . . . . . . . . . 2.65 11.782006 . . . . . . . . . . . . . . . . . . . . . 2.61 11.852005 . . . . . . . . . . . . . . . . . . . . . 2.71 11.902000 . . . . . . . . . . . . . . . . . . . . . 2.62 11.281995 . . . . . . . . . . . . . . . . . . . . . 2.55 11.661990 . . . . . . . . . . . . . . . . . . . . . 2.54 11.92Hispanic5

2008 . . . . . . . . . . . . . . . . . . . . . 0.96 5.742007 . . . . . . . . . . . . . . . . . . . . . 0.97 5.742006 . . . . . . . . . . . . . . . . . . . . . 0.98 5.792005 . . . . . . . . . . . . . . . . . . . . . 0.97 5.692000 . . . . . . . . . . . . . . . . . . . . . 0.94 5.361995 . . . . . . . . . . . . . . . . . . . . . 0.93 5.3619906. . . . . . . . . . . . . . . . . . . . . 0.87 5.231Less than1,500grams(3 lb.4oz.).2Less than2,500grams(5 lb.8oz.).3Includesracesother thanwhiteandblackandoriginnotstated.4RaceandHispanicoriginarereportedseparatelyonbirthcertificates.PersonsofHispanicoriginmaybeofanyrace.Racecategoriesareconsistentwith1977OfficeofManagementandBudgetstandards.Thirtystatesreportedmultipleracedata for2008 thatwerebridged tosingleracecategories forcomparabilitywithotherstates;see TechnicalNotes.Multipleracereportingareasvary for20032008; see TechnicalNotes.5IncludesallpersonsofHispanicoriginofanyrace.6ExcludesNewHampshireandOklahoma,whichdidnotreportHispanicorigin.

TableG.Birthweightdistribution in500-gram intervals:UnitedStates,1990,2006,and2008

Percent

Percentchange

2008 2006 1990 20062008 19902006

Total less than1,000grams. . . 0.70 0.72 0.63 3 141,0001,499grams. . . . . . . . 0.75 0.76 0.65 1 171,5001,999grams. . . . . . . . 1.58 1.63 1.33 3 232,0002,499grams. . . . . . . . 5.14 5.15 4.37 0 182,5002,999grams. . . . . . . . 18.57 18.44 16.03 1 153,0003,499grams. . . . . . . . 39.20 38.87 36.71 1 63,5003,999grams. . . . . . . . 26.41 26.61 29.40 1 94,0004,499grams. . . . . . . . 6.60 6.75 9.10 2 264,5004,999grams. . . . . . . . 0.92 0.96 1.59 4 405,000gramsormore. . . . . . . 0.10 0.11 0.19 9 42
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI10http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI10http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI10http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI10http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI10http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI09


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for nonHispanic whites rose nearly threefold (up 193percent),whereasratesfornonHispanicblackandHispanicmothersincreasedabout90percent.Since1998,thenonHispanicwhitetriplet/+rateisdownbyaboutonethird,whereasnonHispanicblackand Hispanictriplet/+ rateshave fluctuatedonlymodestly.

State-specifictwinandtriplet/+birthratesforcombinedyears20062008areshowninInternetTableI11.Bystate,twinningratesrangedfromalowof24.7per1,000inNewMexicotoahighof43.5inNewJersey.Triplet/+ratesrangedfrom68.7per100,000(Alaska)to260.3 (NewJersey).

References1. Hamilton BE,MartinJA,VenturaSJ.Births:Preliminarydatafor2008.

Nationalvitalstatisticsreports;vol58no16.Hyattsville,MD:NationalCenter forHealthStatistics.2010.

2. National Center for Health Statistics. Natality public use file andCDROM. Hyattsville, MD: National Center for Health Statistics. Pub lishedannually.Available from:http://www.cdc.gov/nchs/data_access/VitalStatsOnline.htm.

3. National Center for Health Statistics. Data release policy. Hyattsville,MD.2000.Available from:http://www.cdc.gov/nchs/nvss/dvs_data_release.htm.

4. National Center for Health Statistics. Vital statistics of the UnitedStates,2003,volume I,natality.

5. National Center for Health Statistics. VitalStats. Available from:http://www.cdc.gov/nchs/VitalStats.htm.

6. National Center for Health Statistics. 2003 revision of the U.S.Standard Certificate of Live Birth. 2003. Available from:http://www.cdc.gov/nchs/nvss/vital_certificate_revisions.htm.7. NationalCenter forHealthStatistics.Reportof thePanel toEvaluatetheU.S.StandardCertificates.2000.

8. MartinJA,HamiltonBE,SuttonPD,etal.Births:Finaldata for2007.Nationalvitalstatisticsreports;vol58no24.Hyattsville,MD:NationalCenter forHealthStatistics.2010.

9. National Center for Health Statistics. User guide to the 2008 natalitypublic use file. Hyattsville, MD. Available from: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdf.

10. OstermanMJK,MartinJA,MenackerF.Expandedhealthdatafromthenewbirthcertificate,2006.Nationalvitalstatisticsreports;vol58no5.Hyattsville,MD:NationalCenter forHealthStatistics.2009.

11. OfficeofManagementandBudget.Revisions to thestandards for theclassification of federal data on race and ethnicity. Fed Regist62FR5878158790.October30,1997.

12. CDC.AdolescentpregnancyandchildbirthUnitedStates,19912008.MMWR60Suppl:1058.2011.

13. Abma JC,MartinezGM, Copen CE.Teenagers in the United States:Sexualactivity,contraceptiveuse,andchildbearing,NationalSurveyofFamilyGrowth20062008.VitalHealthStat23(30).2010.

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TableH.Gestationalageandbirthweightcharacteristics,byplurality:UnitedStates,2008Quintuplets

andhigherorderTwins Triplets Quadruplets multiples1 Singletons

Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138,660 5,877 345 46 4,102,766Percentageverypreterm2 . . . . . . . . . . . . . . . . . . 11.6 38.5 56.5 89.1 1.6Percentagepreterm3 . . . . . . . . . . . . . . . . . . . . . 58.9 93.1 92.2 95.7 10.6Meangestationalage inweeks (standarddeviation). . .Percentagevery lowbirthweight4 . . . . . . . . . . . . . . 35.3 (3.6)10.1 32.0 (3.9)36.1 30.7 (3.9)59.9 28.5 (4.3)82.2 38.7 (2.4)1.1Percentage lowbirthweight5 . . . . . . . . . . . . . . . . . 57.0 94.6 98.6 93.3 6.4Meanbirthweight ingrams(standarddeviation). . . . . . 2,330 (628) 1,666 (567) 1,371 (489) 1,253 (806) 3,296 (561)1Quintuplets,sextuplets,andhigherordermultiplebirthsarenotdifferentiated in thenationaldataset.2Less than32completedweeksofgestation.3Less than37completedweeksofgestation.4Less than1,500grams.5Less than2,500grams.
http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11http://www.cdc.gov/nchs/data_access/VitalStatsOnline.htmhttp://www.cdc.gov/nchs/nvss/dvs_data_release.htmhttp://www.cdc.gov/nchs/VitalStats.htmhttp://www.cdc.gov/nchs/nvss/vital_certificate_revisions.htmftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfhttp://www.census.gov/population/www/socdemo/hh-fam/cps2009.htmlhttp://www.cdc.gov/nchs/data_access/VitalStatsOnline.htmhttp://www.cdc.gov/nchs/nvss/dvs_data_release.htmhttp://www.cdc.gov/nchs/VitalStats.htmhttp://www.cdc.gov/nchs/nvss/vital_certificate_revisions.htmhttp://www.census.gov/population/www/socdemo/hh-fam/cps2009.htmlftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2008.pdfhttp://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_01_tables.pdf#tableI11


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