1. Associate Professor Iolanda Elena Blidaru Md, PhD.
PLACENTA PRAEVIA
Associate Professor
Iolanda Elena Blidaru
Md, PhD.

2. PLACENTA PRAEVIA Definition
Placenta praevia = placental insertion over or very near the internal os of the cervix (in the lower uterine segment including the zone of effacement and dilatation).
obstacle in front of the presenting part
the most frequent cause of third trimester bleeding

3. PLACENTA PRAEVIA

4. PLACENTA PRAEVIA Classification
Depending if the placenta covers the internal cervical os completely or partially:
Total placenta praevia
Partial placenta praevia
Marginal placenta praevia
Low-lying placenta (laterally inserted placenta)

5. PLACENTA PRAEVIA TOTALIS

6. PLACENTA PRAEVIA PARTIALIS

7. PLACENTA PRAEVIA MARGINALIS

8. PLACENTA PRAEVIA
This classification is made on the basis of findings at the initial examination and may change in labor or as pregnancy advances.

9. PLACENTA PRAEVIA Incidence 0.5% -1% of all births
US of early pregnancies - a large number of low-lying pregnancies subsequently aborted.
"placental migration" (US evaluation) → as pregnancy advances, the lower uterine segment lengthens and the placenta is drawn upward with the enlarging uterus.

10. PLACENTA PRAEVIA Risk factors previous cesarean section (x 6)
multiparity(x 2.6)
advanced age
previous D&C
smoking

11. PLACENTA PRAEVIA Etiology
inflammatory or atrophic changes of the endometrium (endometritis, hypoplasia, submucous myomas, trauma) → defective decidual vascularization
twin pregnancy, with large placental bed
increased surface of the placenta implanted in the lower uterine segment (tissues → unappropriate for nidation)

12. PLACENTA PRAEVIA Pathogenesis
painless bleeding → maternal blood + fetal blood (a little part).
Mechanisms:
separation of the placenta from its implantation site
formation of the lower uterine segment
effacement and dilatation of the cervix in labor
rupture of the venous lake in the decidua basalis

13. Associated conditions
PLACENTA PRAEVIA
Associated conditions
placenta accreta → abnormally firm adherence to the uterine wall
placenta increta → placental villi invade the myometrium
placenta percreta → placental villi penetrate through the myometrium

14. PLACENTA PRAEVIA Clinical findings painless bleeding (maternal origin)
slight or profuse hemorrhage
the blood is bright red
postpartal excessive hemorrhage →
abnormal adherence,
excessively large area of attachement,
the poorly contracted lower uterine segment,
lacerations in the cervix and lower segment.

15. PLACENTA PRAEVIA Diagnosis
abdominal examination: abnormal fetal presentation (transverse lie, breech presentation), the presenting part is high above the inlet and deviated anteriorly or laterally
FHR - normal
If cervical os dilated → cautious inspection
digital examination is never permitted unless at term pregnancy, in an operating room with all the preparations for immediate cesarean section; the examination can cause life-threatening hemorrhage.

16. PLACENTA PRAEVIA Diagnosis Sonography transabdominal US (96% accuracy)
transvaginal US
transperineal US

17. Differential diagnosis
PLACENTA PRAEVIA
Differential diagnosis
Cervical bleeding → benign / malignant lesions
Endouterine bleeding:
premature separation of the normally implanted placenta,
rupture of umbilical cord vessels,
premature labor.

18. Practically all women do need cesarean section.
PLACENTA PRAEVIA
DELIVERY MODE
Practically all women do need cesarean section.

19. CONDUCT AT THE DELIVERY
PLACENTA PRAEVIA
CONDUCT AT THE DELIVERY
Several clinical situations:
1. The patient is in labor → cesarean section
2. The fetus is mature and the bleeding does not stop → cesarean section
3. The fetus is preterm and there is no indication for delivery → observe
4. The bleeding is so severe, despite the fetus immaturity → cesarean section
5. Total placenta praevia with dead fetus → cesarean section (the bleeding cannot be controlled).

20. CONDUCT AT THE DELIVERY
PLACENTA PRAEVIA
CONDUCT AT THE DELIVERY
If placenta praevia + accreta, other methods of hemostasis:
oversewing the implantation site
bilateral uterine / inernal iliac artery ligation
packing the lower uterine segment with gauze
total abdominal hysterectomy.

21. CONDUCT AT THE DELIVERY
PLACENTA PRAEVIA
CONDUCT AT THE DELIVERY
Vaginal delivery may be possible in:
a multipara with a soft, effaced and partially dilated cervix + a minor degree of anterior placenta praevia + ruptured membranes
if the fetus is dead, the cervix is soft and effaced, only an edge of placenta can be felt and bleeding is minimal
before the 28th week, when the baby has little chance of surviving

22. PLACENTA PRAEVIA ADDITIONAL TREATMENT adequate transfusion
prophilactic treatment of thrombo-embolism / infectious complications
anti-D Ig
bed rest

23. PLACENTA PRAEVIA Prognosis Maternal Fetal / Neonatal
The perinatal mortality rate → 15-20% (10 times>)
Causes:
prematurity (a major cause)
IUGR
intrauterine anoxia (placental separation, prolapsed cord)
respiratory distress syndrome
exsanguination
fetal malformations