Placental praevia

Question 1

Definition of placental praevia

Answer 1

low-lying placenta

Question 2

Classification of placental praevia

Answer 2

Minor (type I) = Placenta is 0-2cm away from internal OS
Marginal (type III) = Placenta edge is adjacent to edge of OS without covering it
Partial (type II) = Placenta partially covers the OS
Major (type IV) Placenta completely covers the OS

Question 3

SSx of placental praevia

Answer 3

Painless bleed
Small bleeds before large bleeds
Abnormal lie or high presenting part
Spontaneous labour preterm
Non-tender uterus
Fetal heart usually normal

Question 4

Advice to patient

Answer 4

Avoid sexual intercourse while pregnant

Mum can stay at home but remain close to the hospital

Question 5

Risk factors for placenta praevia

Answer 5

Previous history of placenta praevia
Previous caesarean section
Multiparity
Advancing maternal age
Multiple pregnancy
Smoking

Question 6

Treatment for placenta praevia

Answer 6

Asymptomatic minor:
- Normal delivery unless placenta encroaches within 2cm of internal os

Asymptomatic major:
- C-section betwee 36 and 37 weeks

Note: do not perform C-section if placenta located posteriorly or thick

Symptomatic:

• ABCDE
• 2 x large bore cannulas
• 15 minute OBS
• IV fluids
• Give cross-matched blood
• Do bloods: FBC, LFT, Clotting, U & Es
• C-section

Question 7

Clinical tip for placental praeiva?

Answer 7

Do not perform PV exam –> do speculum examination instead

Question 8

Investigation for placenta praevia?

Answer 8

USS +/- MRI

MRI- assess the depth of invasion and
lateral extension of myometrial invasion