Placenta Praevia

Question 1

what is placenta praevia?

Answer 1

placenta lying wholly or partly in the lower uterine segment

Question 2

what are factors associated with placenta praevia?

Answer 2

• multiparity
• multiple pregnancy
• embryos are more likely to implant on a lower segment scar from a previous C-section

Question 3

what are the clinical features of placenta praevia?

Answer 3

• shock in proportion to visible loss
• no pain
• uterus not tender
• lie and presentation may be abnormal
• fetal heart usually normal
• coagulation problems rare
• small bleeds before large

Question 4

when is placenta praevia usually picked up? and what can be used to improve the accuracy of placental localisation?

Answer 4

on the 20 week abdominal US

transvaginal US

Question 5

what are the classical grading of placenta praevia?

Answer 5

I - placenta reaches lower segment but not internal os

II - placenta reaches internal os but does not cover it

III - placenta covers the internal os before dilation but not when dilated

IV - placenta completely covers the internal os

Question 6

what is the bleeding associated with placenta praevia?

Answer 6

painless and bright red

Question 7

what is the bleeding associated with placental abruption?

Answer 7

pain and dark red

Question 8

what is the bleeding associated with vasa praevia?

Answer 8

painless

(+) fetal bradycardia and membrane rupture