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Labor & delivery

Breech presentation

Breech presentation is one of the atypical positions a fetus may present with at term. “Mal–presentations” are fetal positions at delivery other than chin to chest - head first. They include, transverse lie, where the baby is lying horizontal, footling, where a foot is the presenting part, and breech. Breech means that the fetus is positioned with its buttocks or feet presenting first into the birth canal. Before 28 weeks up to 25% of fetuses are in breech position, but by 34 weeks most have rotated into the vertex (headfirst) position.

Common causes for breech include prematurity, low birth weight, fetal abnormalities, multiple gestation (twins or triplets), and uterine abnormalities. Breech presentations can be diagnosed by examining the uterus (feeling for fetal parts by pushing on the uterus) as well as by ultrasound. If the breech is found after 37 weeks, but before labor begins, the baby can sometimes be turned around while in the uterus, a procedure called external cephalic version. The advantage of this procedure may mean that the baby could be delivered vaginally in vertex position.

Version is done by first giving a medication to relax the uterus (e.g. terbutaline). Your clinician and his/her assistant will turn the baby around by pushing the abdomen in specific ways. Fetal monitoring and ultrasound may be used during version to monitor the fetus. Version may be successful up to 75% of the time. It does carry a slight risk of umbilical cord compression and placental abruption or separation, both of which would require immediate c-section. Because of the potential risks involved with “version,” this procedure is done close to the delivery room or birthing center as a precautionary measure.

Under certain conditions it is possible to deliver a breech vaginally but this requires that a number of factors are highly favorable such as fetal size, position, age, and stability, maternal pelvis of adequate size, and the experience of the obstetrician. If any one of these factors is questionable then the breech is generally delivered by cesarean section. The reason for this is that the baby's head is the largest part of its body. If the rest of the body comes through first, and the opening is too small, the head may become stuck. This will necessitate emergency cesarean section and poses potential complications to the newborn.