The The NEWNEW Matched Multiple Matched Multiple Birth File, 1995 - 2000Birth File, 1995 - 2000
Joyce A. Martin, MPHJoyce A. Martin, MPH
Brady E. Hamilton, PhDBrady E. Hamilton, PhD
Candace M. Cosgrove, MPHCandace M. Cosgrove, MPH
Martha L. Munson, MSMartha L. Munson, MS
U.S. Department of Health and Human ServicesCenters for Disease Control and Prevention
National Center for Health StatisticsDivision of Vital Statistics
SOURCE: CDC/NCHS
The MatchedThe Matched Multiple Birth File Multiple Birth File
Allows for research of Allows for research of characteristics of characteristics of SETSSETS of multiple of multiple gestation pregnanciesgestation pregnancies
Includes Includes ALLALL records reported in records reported in twin, triplet and quadruplettwin, triplet and quadruplet deliveries from 1995-2000 NCHS deliveries from 1995-2000 NCHS birth, fetal death and linked birth, fetal death and linked birth/infant death filesbirth/infant death files
SOURCE: CDC/NCHS
The The NEWNEWMatched Multiple Birth FileMatched Multiple Birth File
325,516 325,516 SETSSETS of twins of twins
12,157 12,157 SETSSETS triplets triplets 760 760 SETSSETS of quadruplets of quadruplets
OROR> 699,000 > 699,000 individual recordsindividual records
SOURCE: CDC/NCHS
Definition: multiple deliveryDefinition: multiple delivery
A multiple delivery or multiple A multiple delivery or multiple gestation pregnancy may include any gestation pregnancy may include any combination of live births and fetal combination of live births and fetal deaths; all products of the deaths; all products of the
pregnancy which are pregnancy which are DELIVEREDDELIVERED at any point in the pregnancy are at any point in the pregnancy are counted.counted.
SOURCE: CDC/NCHS
Example:Example:
1 fetal death (1 fetal death (≥ ≥ 20 wks)20 wks)
++2 live births2 live births
==1 triplet pregnancy1 triplet pregnancy
or triplet SETor triplet SET
SOURCE: CDC/NCHS
Twin birth rate:Twin birth rate: U.S., 1980-2002 U.S., 1980-2002
10
15
20
25
30
35
1980 1985 1990 1995 2000 2002
Ra
tio
pe
r 1
,00
0 li
ve
bir
ths
NOTE: Twin birth rate is the number of live born infants in twin deliveries per 1,000 live births.
+65%
0
SOURCE: CDC/NCHS
Triplet/+ birth rate:Triplet/+ birth rate:U.S., 1980-2002U.S., 1980-2002
0
50
100
150
200
250
1980 1985 1990 1995 2000 2002
Rat
e p
er 1
00,0
00 li
ve b
irth
s
NOTE: Triplet/+ birth rate is the total number of live born infants in triplet+ deliveries per 1,000 live births. Triplet/+ includes births in greater than twin deliveries.
SOURCE: CDC/NCHS
Gestational age distributionGestational age distributionby plurality: U.S., 2002by plurality: U.S., 2002
0
5
10
15
20
25
30
32 37 40 42 47
Completed weeks of gestation
Pe
rce
nt
Singletons
Triplets
Less than 28
Twins
SOURCE: CDC/NCHS
Mean birthweightMean birthweightby plurality: U.S., 2002by plurality: U.S., 2002
0
500
1,000
1,500
2,000
2,500
3,000
3,500
Singletons Twins Triplets Quads
Bir
thw
eig
ht
SOURCE: CDC/NCHS
Infant mortality rates by plurality:Infant mortality rates by plurality:U.S., combined years 1999-2001U.S., combined years 1999-2001
0
20
40
60
80
100
120
Singletons Twins Triplets Quads
Per
1,0
00 l
ive
bir
ths
6
107
65
29
6
SOURCE: CDC/NCHS
Percent low birthweight for all birthsPercent low birthweight for all birthsand for singletons: U.S., 1980-2002and for singletons: U.S., 1980-2002
4
6
8
10
1980 1985 1990 1995 2000 2002
Pe
rce
nt
All births/pluralities
Singletons
0
SOURCE: CDC/NCHS
Traditional U.S. Birth FilesTraditional U.S. Birth Files
Infants in multiple deliveries
Unmatched
SOURCE: CDC/NCHS
Matched Multiple Birth FileMatched Multiple Birth File
Infants in multiple deliveries
SOURCE: CDC/NCHS
Matching algorithmMatching algorithm
PluralityState/CountyMother’s DOB
Date of DeliveryUnmatched
records
Add LMPAllow 1 digit Difference inDOB or DOD
Mother’s DOBNot Stated
Add LMP
93%Matched
98.1%Matched
SOURCE: CDC/NCHS
Comparison with MissouriComparison with Missouri1995 matched multiple birth file 1995 matched multiple birth file
2,176 Missouri records reviewed2,176 Missouri records reviewed
NO NO FALSE MatchesFALSE Matches
6 unmatched in NCHS but matched 6 unmatched in NCHS but matched in Missouri filein Missouri file
SOURCE: CDC/NCHS
Records matched by pluralityRecords matched by plurality
0
20
40
60
80
100
Total Twins Triplets Quads
Per
cen
t
95.097.498.998.8
SOURCE: CDC/NCHS
Records matched by outcomeRecords matched by outcome
0
20
40
60
80
100
total Live births Fetal deaths
Per
cen
t
98.8 99.087.5
SOURCE: CDC/NCHS
X gestation 35.4 32.4(weeks)
X birthweight 2,342 1,962 (grams)
% infant deaths 3.0 10.4
Differences in matchedDifferences in matchedvs. unmatched recordsvs. unmatched records
Matched Unmatched
SOURCE: CDC/NCHS
The The NEWNEW Matched Multiple Birth File Matched Multiple Birth File Most data items on birth, fetal deathMost data items on birth, fetal death
and linked infant death records:and linked infant death records:
Maternal age/EducationMaternal age/EducationPrenatal carePrenatal care
Medical risk factors/Tobacco useMedical risk factors/Tobacco useBirthweight/Gestational ageBirthweight/Gestational age
Cause of infant deathCause of infant death
Geographic detailGeographic detailYear of birth/deathYear of birth/death
SOURCE: CDC/NCHS
Uses of the Matched Multiple Birth FileUses of the Matched Multiple Birth File
Birthweight discordanceBirthweight discordanceSet gender Set gender SIDSSIDSGrowth restrictionGrowth restrictionOlder momsOlder momsSet orderSet orderParityParity
SOURCE: CDC/NCHS
TheThe NEWNEW Matched Multiple Birth FileMatched Multiple Birth File
[email protected]@cdc.gov
[email protected]@cdc.gov
[email protected]@cdc.gov
