Placenta Praevia

Question 1

Define placenta praevia

Answer 1

The placenta is fully or partially attached to the lower uterine segment

Minor = low but does not cover the internal Os

Major = lies over the internal Os

More susceptible to haemorrhage

Question 2

What are the risk factors for placenta praevia

Answer 2

• Previous caesarean section
• High parity
• Maternal age >40 years
• Multiple pregnancy
• Previous placenta praevia
• Hx of uterine infection (endometritis)
• Curettage to the endometrium after miscarriage or termination

Question 3

How does placenta praevia present?

Answer 3

PAINLESS vaginal bleeding (vs abruption pain is constant), that increases as gestation continues (sheering forces increase)

Examination may reveal risk factors pertinent to placenta praevia – e.g. c-section scar or multiple pregnancy.

Question 4

Outline how suspected placenta praevia should be investigated

Answer 4

Bloods = FBC, clotting, Kleihauer test, G+S, X match, U+Es, LFTs

Cardiotocograph (CTG)

TV US (>2.5cm from cervix = -ve)

Question 5

Describe the management of placenta praevia

Answer 5

A-E for significant antepartum haemorrhage + anti-D

Placenta praevia minor = repeat scan at 36w, placenta likely to have moved superiorly.

Placenta praevia major = repeat scan at 32w, and a plan for delivery should be made

Confirmed = CS safest form of delivery at 38w