Placenta Previa

Question 1

What is placenta previa?

Answer 1

The placenta lies wholly or partly in the lower uterine segment.

Question 2

What are some associated factors with placenta praevia?

Answer 2

• Multiparity
• Multiple pregnancy
• Embryos are more likely to implant on a lower segment scar from previous caesarean section

Question 3

What are some 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

Describe the grading of placenta praevia?

Answer 4

• I - placenta reaches lower segment but not the internal os
• II - placenta reaches internal os but doesn’t cover it
• III - placenta covers the internal os before dilation but not when dilated
• IV - placenta completely covers the internal os

Question 5

At 16-20 weeks, 5% of patients will have a low lying placenta. Does this increase or decrease by the time of delivery?

Answer 5

Decreases - placentas rise away from the cervix.