Placenta Praevia

Question 1

What is placenta praevia? What are the types?

Answer 1

Implantation of the placenta in front of the presenting part and internal os

• Major - placenta lying over the cervical os
• Minor - placenta not lying over the cervical os but encroaching on the lower uterine segment

Question 2

What are some risk factors for placenta praevia?

Answer 2

• Major - placenta lying over the cervical os

- Minor - placenta not lying over the cervical os but encroaching on the lower uterine segment

Question 3

What proportion of APH does it cause?

Answer 3

20%

Question 4

What is the incidence? Why does it change?

Answer 4

5% at 16-18 weeks

0.5% at term

Question 5

How does it present?

Answer 5

Identified on routine US scanning
Bleeding
Malpresentation of the fetus due to placenta preventing engagement

Question 6

What proportion of women with it bleed?

Answer 6

70-80% - often following intercourse or vaginal exam

Question 7

What must be avoided in the presence of PP?

Answer 7

Vaginal examination

Question 8

How is PP managed in the antepartum period?

Answer 8

If symptomatic minor or major - hospital admission is required from 32 weeks for the duration of pregnancy

If asymptomatic minor then can be mx as an outpatient

Question 9

What are indications for delivery? Short and long term

Answer 9

Short term
- Fetal or maternal demise (CTG and vitals respectively)

Long term

• Fetus: IUGR, premature rupture of membrane, vasa praevia
• Adequate gestation therefore when risks of staying in uterine out weigh the risk of delivery

Question 10

How is PP delivered?

Answer 10

CS usually - lower uterine segment through placenta - must be fast
Vaginal is possible if not fully obstructed