Prolonged Pregnancy

Question 1

Define prolonged pregnancy

Answer 1

Pregnancies which persist up to and beyond 42 weeks gestation

Question 2

What are the risk factors for prolonged pregnancy?

Answer 2

• Nulliparity
• Maternal age >40
• Previous prolonged pregnancy
• High BMI
• FH of prolonged pregnancies

Question 3

Outline the possible complications of prolonged pregnancy

Answer 3

Stillbirth:
37/40 – 1 in 1000
42/40 – 3 in 1000
43/40 – 6 in 1000

Due to the increased potential for placental insufficiency, there is also a higher risk of fetal acidaemia and meconium aspiration in labour, and the need for instrumental or caesarean delivery.

Reduced O2 and nutrient transfer due to placental degradation can deplete fetal glycogen stores, resulting in neonatal hypoglycaemia.

Question 4

What are the typically clinical features of a prolonged pregnancy?

Answer 4

Static growth or potentially macrosomia

Oligohydramnios

Reduced fetal movements

Presence of meconium

Signs of meconium staining e.g. on nails

Dry / flaky skin with reduced vernix (vernix is a waxy, white substance found coating the skin of newborn babies)

Question 5

How should prolonged pregnancy be investigated?

Answer 5

Dating = between 11+0 and 13+6 weeks gestation

US = check growth, liquor volume

Question 6

Outline the management of prolonged pregnancy

Answer 6

NICE/RCOG guidelines recommend delivery by 42 weeks gestation to reduce the risk of stillbirth in prolonged pregnancy =

1) Membrane sweeps – can be offered from 40+0 weeks in nulliparous and 41+0 weeks in parous women
2) Induction of labour – usually offered between 41+0 and 42+0 weeks gestation