Placenta Praevia

Question 1

define:

low-lying placenta

placenta praevia

Answer 1

within 20mm of the internal os

overlying the internal os

Question 2

how common is placenta previa?

Answer 2

1% of pregnancies

Question 3

how does placenta praevia typically present?

when?

Answer 3

they are mostly asymptomatic but can present with

antepartum haemorrhage (painless)

generally at about 36 weeks gestation

Question 4

how is placenta praevia generally diagnosed?

Answer 4

it can be detected on the anomaly scan at 20 weeks

Question 5

6 risk factors for placenta praevia

Answer 5

previous C-sections

previous placenta praevia

older maternal age

maternal smoking

IVF

structural abnormality of the uterus e.g. large fibroids

Question 6

at how many weeks gestation are patients with placenta praevia reassessed?

Answer 6

at 32 and 36 weeks

sometimes as the uterus grows the placenta moves out of the way of the os

Question 7

how is delivery managed in patients with placenta praevia?

Answer 7

generally elective delivery is carried out at 36 or 37 weeks gestation by Caesarean

Question 8

how are caesareans different in placenta praevia?

Answer 8

the incisions may be made differently depending on where the placenta is

the position of the placenta may be assessed using USS during the operation

Question 9

suggest how premature labour would be managed in a patient with a placenta praevia

Answer 9

with an emergency c-section

Question 10

3 methods of arresting bleeding in antepartum/post-partum heamorrhage

Answer 10

intra-uterine balloon

uterine artery occlusion

emergency hysterectomy

Question 11

true or false: placenta praevia can result in a reduced foetal growth

Answer 11

true; presumably the blood flow to the foetus is compromised in some way