Transcript Placenta Previa - Isfahan University of Medical Sciences

Placenta Previa
Dr .M Movahedi
Assistant professor of Ob& Gyn of
IUMS
Definition
• The presence of placental tissue overlying
or proximate to the cervical os .
Several forms of PP :
• Complete PP .
• Partial PP .
• Marginal PP
• Low – lying PP . ( within 2-3 cm os . )
Iincidence : PP
• 4/1000 pregnancy over 20 weeks
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 :
• 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 :
• 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
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mal presentation
PPROM
IUGR : 16%
Congenital anomaly
Diagnosis : PP
• Ultrasound
• Clinic :
• Painless VB > 24 weeks
Differential diagnosis :
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Third trimester bleeding 3-4% : pregnancy
Abruptio placenta ( 31% )
PP ( 22% )
Other cause ( 47% ):
labor
rupture
neoplasm
Ultrasonography
Trans vaginal : gold standard _ safe _ effective
technique .
• accuracy than 99%
Trans labial ultrasound
• excellent images
Trans 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 :
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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
MRI :
• Posterior previa
• High cost
• Limited availability
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 :
• 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
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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 .
• 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
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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
• 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 :
• Tocolysis : controversial _ hemodynamically
stable & uninfected women
• Corticosteroid < 32 weeks
Out patient management :
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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
Timing :
• FHR
• Life threatening material hemorrhage
• After 34 weeks : presence fetal pulmonary
maturity .
• Amniocentesis at 36 weeks : repeat every
week .
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 :
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General
Maternal mortality : 1 %
perinatal mortality : 10 %
Principal causes of prenatal mortality
* Preterm delivery
*Fetal anemia
*Hypoxia
*Growth restriction
Recurrence rate : 4 _ 8 %
Pregnancy termination :
• Termination at 13 _ 24 weeks : laminaria
D&E ( blood loss )
• Associated conditions :
• Velamentous umbilical lord
• Vasa previa
• Placenta accreta
Velamenous umbilical cord :
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Vessels surrounded by fetal memberan,no whartons jelly
1% singleton
10% multiple gestation
25% fetal anomalies
sonography : umbilical cord insertion, 12.5 __ single
umbilical artery
Diagnosis : color Doppler , flow
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 :
• low lying placenta previa
• monochorionic twin gestations
• velamentous cord insertion
• multi lobed placenta
• IVF
• Diagnosis : VB + abnormality of FHR (sinusoidal
pattern)
• Ultrasound color Doppler
vasa previa
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___ cord movement
• Termination : C/S 35- 36 weeks ( corticosteroids )
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Placenta accreta :
• 5_ 10 % : with PP
• 25 % : PP + one P C/S
• 50 % : PP + 2 or more P C/S
Abruptio placenta
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
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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 :
Catastrophic trauma
PPROM
Chronic pathologic vascular process ( IUGR _
preterm labor )
Risk 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 : server & chronic, 5 folds server
Abruption
• Antihypertensive therapy dose not reduce risk
of Abruption
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 & parity 2.5 %
• Endometrial scarring & impaired
decidualization
cocaine abuse : 10%
• Acute vasoconstriction
ischemia
reflex
vasodilation
bleeding
PPROM : 2 - 5 % AP
• Infection or oligohydramnios
7 to 9 fold
• Abruption
thrombin
proteas PPROM
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inherited 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 :
• Ten folds . AP
multifetal gestation & polyhydramnios
• 3 folds AP
• cause : rapid uterine decompression upon
delivery of one twin .
others :
• folate deficiency , leiomyoma ,
circumvallata placenta
Clinical manifestation
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VB > 80%
Abdominal pain > 50%
Uterine contraction ( tachy systole )
Uterine tenderness
FHR
Uterine tone
Back pain : posterior placenta
Preterm birth
Chronic abortion
Concealed hemorrhage
• 20%
• placental margins remain adherent
• The fetal membrane retain their
attachment to the uterine wall
• The fetal head obstruct cervical os
Coagulopathy
• server abruption with death fetus
coagulopathy
• hypofibringenemia
• DIC
• Kidney
• Fetus : BPP
• Utero placental insufficiency
20%
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 :
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Placenta previa
Vasa previa
Labor
Uterine rupture
Cervicovaginal neoplasm
Abdominal disorder ( pain without bleeding )
Management
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Initial approach :
Closely monitoring
Large _ Bore IV
Maternal hemodynamic status:
BP- PR-Out Put - BG Rh- HCT- PLT-Fib- PTPTT
• Normotensive + normal HCT & Abruption :
• Previousely hypertensive & acute bleeding
management
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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
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Delivery : optimal treatment
Mild Abruption : Expectant management
Corticosteroid therapy < 34 weeks
tocolysis < 34 weeks
Labor :
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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 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
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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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