Placenta PreviaPlacenta PreviaDr .M Movahedi

Assistant professor of Ob& Gyn of IUMS

DefinitionDefinition

• The presence of placental tissue overlying or proximate to the cervical os .

Several forms of PP : Several forms of PP :

• Complete PP .

• Partial PP .

• Marginal PP

• Low – lying PP . ( within 2-3 cm os . )

Iincidence : PP Iincidence : PP • 4/1000 pregnancy over 20 weeks

Risk factors :Risk factors :_ parity ( 0/2% nullipara – 5% grand multipara _ maternal age : • 0/03 % nullipara 20 < age < 29 • 0/25 % nullipara > 40 year_ number of perior c/s : • ( incidence 10% after 4 or more ) _ number of curettage for spontaneous or induced abortion _ maternal smoking : _ residence at higher altitudes _ male fetus_ multiple gestation ( 39/1000 twin live and 2.8 previa /1000 lit) _ gestational age : early pregnancy

Pathogenesis of PP : Pathogenesis of PP :

• Endometrial scarring in the upper segment

• Initial tropnoblastic nidation or unidirectional growth into LS .

• Increased placental surface to compensate for a reduction in uteroplacental oxygen

• the length of lower uterine segment 0/5cm(20 weeks )

• 5 cm ( at term )

Clinical manifestations : Clinical manifestations : • Painless vaginal bleeding ( 70 – 80 % ) VB + uterine contraction : ( 10 – 20 % ) • Asymptomatic (ultrasound ) : ( <10 % ) Initial bleeding : typically 34 weeks • 1/3 : Bleeding prior to 30 weeks Blood

transfunsions & preterm delivery & perinatal mortality

• 1/3 : VB 30 - 36 weeks • 1/3 : VB after 36 weeks contraction - vaginal

exam - Coitus vaginal Bleeding

Associated conditions : PP Associated conditions : PP

• mal presentation

• PPROM

• IUGR : 16%

• Congenital anomaly

Diagnosis : PP Diagnosis : PP

• Ultrasound

• Clinic :

• Painless VB > 24 weeks

Differential diagnosis : Differential diagnosis :

• Third trimester bleeding 3-4% : pregnancy

• Abruptio placenta ( 31% )

• PP ( 22% )

• Other cause ( 47% ): labor

rupture

neoplasm

Ultrasonography Ultrasonography Trans vaginalTrans vaginal : gold standard _ safe _ effective

technique .• accuracy than 99% Trans labial ultrasoundTrans labial ultrasound • excellent images Trans abdominal ultrasoundTrans abdominal ultrasound • accuracy 95% • false negative rate 7%

• ** an over distended bladder for anterior previa

• ** for posterior previa : Trendelenburg position

Persistence after second trimester diagnosis : Persistence after second trimester diagnosis :

• 10 _ 20 weeks GA 4 _ 6% PP • 10 folds third trimester (0/4 % )

• Complete previa • Amount of overlap • Overlap (20 - 23 w)> 25 mm persistence 40%

• Overlap < 14 to 15 mm 20% • Repeat ultrasound: 28 w and 34 w

Exclusion of placenta accreta Exclusion of placenta accreta MRI : MRI : • Posterior previa

• High cost

• Limited availability

Antepartum management Antepartum management

• General principles :

• Sonography

• Avoidance of coitus & digital cervical examination & exercise & decrease activity

• Counseling to seek immediate medical attention if VB

Acute care of symptomatic PP : Acute care of symptomatic PP : • admit to the labor • maternal & fetal monitoring • large bore IV & crystalloid & hemodynamic

stability & adequate urine out put . • Type a cross _ match for four units packed

blood cells . (Actively bleeding HCT > 30 ) • maternal cardiac monitor: BP &PR every 15

min/h • FHR : continuously monitored . • FHR or FHR or sinusoidal : Anemia & Hypoxia

• quantitative monitoring of VB loss

• Urine output : hourly with Foley catheter

• Laboratory monitoring

• HB-HCT /q 4 -6 h

• Serum electrocytes & indexs of renal function:every 6-8 / h

• PT _ PTT _ CBC _ PLT- fibrinogen

• DIC delivery

• Unstable hemodynamic or underlying disease (cardiac& pulmonary) place swan Ganz catheter ( CVP )

• ( PCWP ) & cardiac out put

• Tocolysis is not administeral to VB If : VB or ceased

Delivery indicated . Delivery indicated . • FHR • Life threatening maternal VB • VB after 34weeks & in presence of pulmonary

maturity • C/S : choice • ND : hemodynamical stability & fetal demise &

previable fetus & some cases of marginal previa

• Anesthesia : G A for emergency Cs

• Regional A for stable patients

• RH ( D ) negative women

• RH ( D ) _ Immune globulin .

Conservation management of stable preterm patients Conservation management of stable preterm patients

• Hospitalized at bed rest , minimize constipation ( high fiber diet & stool softens ) • Periodic maternal HCT • Ferrous gluconate supplements ( 3- 4 time/day ) + vitamin

C • Maternal blood sample type, cross match ( 2 _ 4 units P.C )

HCT > 30 • Corticosteroid therapy : ( 24 _ 34 weeks ) • RH ( D ) _ immunoglobolin : ( 3 weeks ) • Fetal Heart rate monitoring : • sonography : IUGR _ AF _ placenta location • Tocolysis : contraction ( Mg so4 4 H2o ) • Cervical cercelage : longer gestations heavier birth

weight , reduction in antenatal hospitalization .

PPROM & PP : PPROM & PP :

• Tocolysis : controversial _ hemodynamically stable & uninfected women

• Corticosteroid < 32 weeks

Out patient management : Out patient management : • Restriction activity • 48 h after stopped bleeding • Live within 15 min of the hospital • Have an adult companion available 24h/day ( for transport & cell ambulance ) • Be reliable & able to maintain bed rest at home . • understand the risks of PP . • Benefits of out patients • Longer duration of pregnancy ( 33- 36 w ) higher

mean birth weight • Lower over all cost

Delivery Delivery

Timing :

• FHR

• Life threatening material hemorrhage

• After 34 weeks : presence fetal pulmonary maturity .

• Amniocentesis at 36 weeks : repeat every week .

Procedure :Procedure :• Abdominal delivery ( complete previa ) • Expect : fetal demise _ previable fetus marginal PP

placenta > 2 cm from OS • C/S : placenta within 2 cm of internal • Available 2 to 4 units PC . • Surgical instruments : CS hysterectomy • 5 - 10 % risk placenta accreta . • Pre operative sonographyic localization of placenta .• Incised placenta : delivered rapidly & cord clamped to hemorrhage from fetus .

Out come PP : Out come PP :

• General General • Maternal mortality : 1 % • perinatal mortality : 10 % • Principal causes of prenatal mortality • * Preterm delivery • *Fetal anemia• *Hypoxia • *Growth restriction • Recurrence rate :Recurrence rate : 4 _ 8 %

Pregnancy termination : Pregnancy termination : • Termination at 13 _ 24 weeks : laminaria

D&E ( blood loss )

• Associated conditions :

• Velamentous umbilical lord

• Vasa previa

• Placenta accreta

Velamenous umbilical cord : Velamenous umbilical cord : • Vessels surrounded by fetal memberan,no whartons jelly • 1% singleton • 10% multiple gestation • 25% fetal anomalies • sonography :sonography : umbilical cord insertion, 12.5 __ single

umbilical artery • Diagnosis :Diagnosis : color Doppler , flow • Obstetric complications :Obstetric complications : IUGR - Prematurity _ congenital

anomalies low APGAR scores , fetal bleeding, retained placenta .

• Cord compression by fetal descending fetal death . • Pregnancy should not be allowed to proceed beyond 40

weeks .

Vasa previa :Vasa previa :• low lying placenta previa • monochorionic twin gestations • velamentous cord insertion • multi lobed placenta • IVF • Diagnosis :Diagnosis : VB + abnormality of FHR (sinusoidal

pattern) • Ultrasound color Doppler Ultrasound color Doppler vasa previa • ___ cord movement • Termination : C/S 35- 36 weeks ( corticosteroids ) •

Placenta accreta :Placenta accreta :

• 5_ 10 % : with PP

• 25 % : PP + one P C/S

• 50 % : PP + 2 or more P C/S

Abruptio placenta Abruptio placenta

Introduction : Introduction : • A.P : premature separation of a normally implanted

placenta after 20 weeks but prior to delivery infant .

Immediate cause : • Rupture of defective maternal vessels in decidua• basallis

Rare cause :• Bleeding fetal _ placenta vessels . • Separation of placenta : hematoma • Retro placenta complete partial

exchange gases nutrient to the fetus

Incidence Incidence • 0/4 to 1/3% ( 1/75 _ 1/225 )

• Incidence to be increasing • Sever AP to still birth : 1/ 830 • 1/3 antepartum bleeding ___ AP • Pathogenesis :Pathogenesis :• Catastrophic trauma • PPROM• Chronic pathologic vascular process ( IUGR _

preterm labor )

Risk factors : Risk factors : mechanical factors :mechanical factors :• Truma : external compression decompression ,

rapid acceleration _ deceleration present within 24h of event Monitoring : 4_ 6 h period ( VB _ tenderness ) Sudden internal decompression of the

uterus : PPROM • Placental implantation over uterine anomaly or

myoma Hypertension :Hypertension : server & chronic, 5 folds server

Abruption • Antihypertensive therapy dose not reduce risk

of Abruption

cigarette smoking :cigarette smoking : 2.5 fold server A.P Risk : 40% / pocket / day Mechanism : ischemic peripheral necrosis of

decidua cigarette smoker & hypertension are synergistic .

maternal age & paritymaternal age & parity 2.5 % • Endometrial scarring & impaired

decidualization cocaine abuse :cocaine abuse : 10% • Acute vasoconstriction ischemia

reflex vasodilation bleeding

PPROM :PPROM : 2 - 5 % AP • Infection or oligohydramnios 7 to 9 fold• Abruption thrombin proteas PPROM

inherited thrombophiliainherited thrombophilia : : 1/5 – 12 folds • factor V leiden: • maternal venous thromboembolism , fetal death

,IUGR , sever PIH , abruption • Prc ,Prs , Antithrombin • VII , VIII , IX , XI • Hyperhomocysteinemia : 31% Ab • Congenital hypofibrinogenemia

afibrinogenemia, XIII AP : (Heparin & folate)

Previous Abruption :Previous Abruption : • Ten folds . AP multifetal gestation & polyhydramniosmultifetal gestation & polyhydramnios • 3 folds AP • cause : rapid uterine decompression upon

delivery of one twin . others : others : • folate deficiency , leiomyoma ,

circumvallata placenta

Clinical manifestation Clinical manifestation • VB > 80% • Abdominal pain > 50% • Uterine contraction ( tachy systole ) • Uterine tenderness • FHR• Uterine tone• Back pain : posterior placenta • Preterm birth • Chronic abortion

Concealed hemorrhageConcealed hemorrhage

• 20%

• placental margins remain adherent

• The fetal membrane retain their attachment to the uterine wall

• The fetal head obstruct cervical os

Coagulopathy Coagulopathy

• server abruption with death fetus 20% coagulopathy

• hypofibringenemia

• DIC

• Kidney

• Fetus : BPP

• Utero placental insufficiency

Diagnosis :Diagnosis :• Clinic

• Sonography _ difficult

• Laboratory not useful _ CA 125, D- Dimer _ thrombo modolin -Fibrinogen 200 mg / dl-PLT

• Pathologic findings:

• Clot depression Maternal surface of placenta

Differential diagnosis :Differential diagnosis :

• Placenta previa

• Vasa previa

• Labor

• Uterine rupture

• Cervicovaginal neoplasm

• Abdominal disorder ( pain without bleeding )

Management Management • Initial approach :

• Closely monitoring

• Large _ Bore IV

• Maternal hemodynamic status:

• BP- PR-Out Put - BG Rh- HCT- PLT-Fib- PT- PTT

• Normotensive + normal HCT & Abruption :

• Previousely hypertensive & acute bleeding

• Fetal monitoring• Crystalloid infusion • RBC , packed cells • 300 cc packed cell 200 cc RBC 3-4% HCT• PT & PTT( 1/5 times): 2 units FFP • 5 units packed cell: PTT- PT - fibrinogen - PLT • PLT < 50,000 : 6 units of PLT • Tocolysis : contraindication ( sever abruption ,

DIC FHR

managementmanagement

• Delivery :Delivery : optimal treatment

• Mild Abruption : Expectant management

• Corticosteroid therapy < 34 weeks

• tocolysis < 34 weeks

Labor : Labor : • Monitoring on labor room . • Mode & timing delivery :• Condition & gestational age• Condition ( BP , DIC , Hemorrhage status of cervix , FHR ) • VD : Amniotomy _ Internal & monitoring of fetus &

intrauterine press catheter • Pressure > 25 abnormal uterine flow oxygenation of

fetus • Poor condition sever hypertone , hemorrhage ,DIC, FHR

• C/S : HCT > 25% , fibrinogen (150- 200 mg/dl ), PLT >

60,000 • Anesthesia : GA • Appropriate mode of delivery : C/S• ( VD : cervical dilation in Parous women

Out comeOut come• Perinatal mortality 20% (still birth, 50% placenta

separation) • IUGR• Prematurity : 4 folds • C/S : 3 /4 delivery ( Sweden ) • Midtrimester abruption poor prognosis • Recurrence risk : 5 _ 15 % • Base line risk : o/4% to 1/3% • Two abruption: risk 25% • Sever abruption: ( dead fetus ) 7% • Abruption & subsequent pregnancy :• Abruption • SGA • Preterm labor • PIH

Management in subsequent pregnancy Management in subsequent pregnancy

• Risk factors : Cigarette • Thromboprophylaxis : Thrombophialias • SGA • Preterm labor • Six weeks prior GA of initial abruption • Elective C/S 39 to 40 • recurrent abruption & fetal death • Preterm Delivery after lung maturition

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