Epidural pain relief is an increasingly popular choice for Australian women in the labour ward. Up to one-third of all birthing women have an epidural, and it is especially common amongst women having their first babies. For women giving birth by caesarean section, epidurals are certainly a great alternative to general anaesthetic, allowing women to see their baby being born, and to hold and breastfeed at an early stage: however their use as a part of a normal vaginal birth is more questionable.
There are several types of epidural used in Australian hospitals. In a conventional epidural, a dose of local anaesthetic is injected through the lower back into the epidural space, around the spinal cord. This numbs the nerves which bring sensation from the uterus and birth canal. Unfortunately, the local anaesthetic also numbs the nerves which control the pelvic muscles and legs, so with this type of epidural, a woman usually cannot move her legs and, unless the epidural has worn off, cannot push her baby out, in the second stage of labour.
One of the most commonly recognised side effects is a drop in blood pressure. Up to one woman in 8 will have this side effect to some degree, and for this reason, extra fluids are usually given through a drip to prevent problems. A drop in the mother’s blood pressure will affect how much of her blood is pumped to the placenta, and can lead to less oxygen being available to the baby.
An epidural will often slow a woman’s labour, and she is three times more likely to be given an oxytocin drip to speed things up. The second stage of labour is particularly slowed, leading to a three times increased chance of forceps. Women having their first baby are particularly affected; choosing an epidural can reduce their chance of a normal delivery to less than 50%.
This slowing of labour is at least partly related to