Shoulder dystocia is where the foetus' shoulder gets stuck
on the way through the birth canal. This can cause injury to the infant
or block the infant's ability to breath.
Incidence is directly related to fetal size: (>2500 g 0.15%;
>4000 g 1.7%; >4500 g 10.0%). Factors such as gestational diabetes, a
history of large infants, large maternal size, a prolonged gestation,
or if second stage is prolonged may also increase the risk of shoulder
Usually a is performed if there is a risk of shoulder dystocia or if
the infant can can pass through the birth canal.
The information in this page is presented in summarised form and has been taken
from the following source(s):
1. University of Iowa Family Practice Handbook: