placenta praevia

1. Dr . N SRAVANTHI Dr . NEHA GUPTA Dr . SEEMA CHOPRA ANTEPARTUM HAEMORRHAGEPLACENTA PREVIA

2. Definition “bleeding into or from the genital tract after 24 weeks of gestation” “ Bleeding from the female genital tract anytime after fetal viability but beforedelivery” (WHO ) Affects 3-5% of all pregnancies. 3 times more common in multiparous than primiparous women .

3. Classification

5. Placental abruption 22%

6. Unclassified 47%

7. – Marginal 60%

8. – Show 20%

9. – Cervicitis 8%

10. – Trauma 5%

11. – Vulvovaginal varicosities 2%

12. – Genital tumours 0.5%

13. – Genital infections 0.5%

14. – Haematuria 0.5%

15. – Vasa praevia 0.5%

17. definition Placenta praevia is defined as the presence of placental tissue over or adjacent to the cervical os. In other words “ when part or all of the placenta in the lower uterine segment” INCIDENCE: overall 4/1000 deliveries In 2nd trimester may be found in 4-6 % pregnancies…. 0.5 to 1% term Gabbe obstetrics 5th edition

18. Hypothesis for resolution of placenta praevia at term As pregnancy advances, stationary lower placental edge relocates away from os with development of LUS. Trophotropism: growth of trophoblastic tissue away frm cervical os towards the fundus resulting in resolution For a placental edge reaching or overlapping the internal os, incidence - 42% between 11 and 14 weeks, 3.9% between 20 and 24 weeks, and 1.9% at term.(Ultrasound ObstetGynecol2002)

19. Classification Type 1 (Lateral or low lying): edge of placenta encroaches on lower segment but not upto int. os Type 2(Marginal): lower edge extends to but not across the os Type 3(Partial): placental edge extends assymetrically across the os but doesn’t cover it completely after cervical dilatation Type 4(Complete or central): placenta placed over the os and likely to cover even after full cervical dilatation

23. >40 years 9 fold increased riskCigarette smoking Residence at higher altitudes Multiple gestations Previous placenta praevia Prior curettage Prior cesarean delivery

24. Clinical manifestations Typical presentation : painless vaginal bleeding. Post coital bleeding Recurrent bleeding Malpresentation Unstable lie High presenting part

25. DIAGNOSIS (TAS Vs TVS) 26-60% of women who undergo (TAS) may have a reclassification of placental position when they undergo TVS With TAS, there is poor visualization of the posterior placenta, the fetal head can interfere with the visualization of thelower segment, obesity and underfilling or overfilling of the bladder, interfere with accuracy

26. TAS is associated with a false positive rate for the diagnosis of placenta previa of up to 25% Accuracy rates for TVS are high sensitivity 87.5%, specificity 98.8%, positive predictive value 93.3%, Negative predictive value97.6% safe in the presence of placenta praevia, even when there is established vaginal bleeding SOGC CLINICAL PRACTICE GUIDELINE No. 189, March 2007

27. Translabial/Transperineal US Superior to abdominal views in both diagnosis and exclusion Affords a quick , accurate and well tolerated view of cervix to ascertain length and placental localisation relative to internal os Improved spatial and contrast resolution Less interposed soft tissues and diminished accoustic attenuation

28. ROLE OF MRI accurately image the placenta and is superior to TAS unlikely that it confers any benefit over TVS for placental localization Not readily available SOGC CLINICAL PRACTICE GUIDELINE No. 189, March 2007

29. Transabdominal ultrasound of a low-lying placenta. The lower edge of the placenta is 18 mm away from the endoncervix (callipers)

30. Transvaginal ultrasound of a complete placenta previa that appears to be central (asterisk–placenta; arrows–endocervical canal).

31. Transvaginal ultrasound of a complete placenta previa that is not central

32. Transvaginal sonogram in the second trimester demonstrating form of placenta praevia. In this case, the inferior placental edge is shown to encroach upon the posterior cervix but not reach or cover the internal cervical os (arrow).

33. Example of incomplete previa demonstrated by transvaginal ultrasound. In this case, the inferior placental edge (Pl) extends onto the cervix posteriorly and is located approximately 1 cm from the internal cervical os (arrow).

34. Transvaginalsonography Reporting of the actual distance from the placental edge to the internal cervical os in milimeters or in mm of overlap placental edge exactly reaching the internal os is described as 0 mm between 18 and 24 weeks‘ gestation (incidence 2 to 4%) If overlap >15mm increased likelihood of placenta praevia at term a follow-up examination for placental location in the third trimester

35. Between 20 mm away from the internal os and 20 mm overlap after 26 weeks' gestation, repeated USG at regular intervals depending on the gestational age, distance from the internal os, and clinical features such as bleeding, because continued change in placental location is likely. Overlap of 20 mm or more at any time in the third trimester is highly predictive of the need for Caesarean section (CS)

36. Management

39. MANAGEMENTExpectant Management of Patients remote from term Patients with placenta praevia who present preterm with vaginal bleeding hospitalization and immediate evaluation to assess maternal-fetal stability.

40. should initially be managed in a labor and delivery unit with continuous fetal heart rate and contraction monitoring Large-bore intravenous access and baseline laboratory studies (hemoglobin, hematocrit, platelet count, blood type and screen, and coagulation studies) should be obtained. IF <34 WKS : Administer antenatal corticosteroids Tocolysis : If the vaginal bleeding is preceded by or associated with uterine contractions.

41. Role of cervical encirclage In one study, there was a reduction in the risk of delivery before 34 weeks or the birth of less than 2000g There is insufficient evidence to recommend the practice of cervical cerclage to reduce bleeding in placenta praevia. RCOG 2011

42. OUTPATIENT MANAGEMENT IN PLACENTA PRAEVIA Outpatient management of placenta previa may be appropriate for stable women with home support, Close proximity to a hospital, and readily available transportation and telephone communication. RCOG 2011

44. usg confirmed placenta praevia-

45. matched blood be available all the times

46. anemia to be treated

47. if gestation <34 antenatal corticosteroids

49. Route of delivery at term The os–placental edge distance on TVS after 35 weeks' valuable in planning route of delivery. > 20 mm away from the internal cervical os, can be offered a trial of labour . A distance of 20 to 0 mm away from the os - higher CS rate Any degree of overlap (> 0 mm) after 35 weeks is an indication for Caesarean section for delivery.

50. Caeseraen section in placenta praevia(technical considerations) Pfannensteil incision adequate in most situations If placenta anterior- best not to cut through the placenta Best to use hand to separate placenta to the nearest edge Rupture the membranes, deliver the baby n promptly clamp the cord

51. The site of placental implantation in non-contractile LUS may continue to ooze can cause alarming bleeding Other options : Ballontamponade, Uterine and ovarian artery ligation, Full thickness horizontal or square compression sutures If above procedures fail -> ligation of anterior division of int. illiac artery T/t - pressure packing of the LUS for 4 minute Dicrete points of bleeding identified n oversewn by figure of eight

52. METHOD OF ANAESTHESIA FOR CAESAREAN SECTION Regional anaesthesia is safe When prolonged surgery is anticipated in women with prenatally diagnosed placenta accreta, general anaesthesia may be preferable Regional anaesthesia could be converted to general anaesthesia if undiagnosed accreta is encountered SOGC CLINICAL PRACTICE GUIDELINE No. 189, March 2007

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