When a labouring woman is able to freely move during birth it helps her deal with the intensity of the contractions and it also allows her to move into positions that help open up the pelvis to make room for the baby. This helps apply pressure on the cervix, and in Second Stage labour allows gravity to help move the baby down into the birth canal. When a woman has an epidural she is required to lie on her back, perhaps with short periods on her side (although this can cause the analgesia to drain into the lower part of her body and increase sensations on the upper side) – so she is no longer able to be active in the labour. Contractions can also slow down which may prolong the labour and cause the need for syntocin (artificial oxytocin) to keep the uterus contracting.

Furthermore, Second Stage labour is severely compromised because the woman will not be able to feel the fetal ejection reflex—a natural sensation caused by the baby descending, and in this case less likely to occur as the baby is not descending naturally by the actions of gravity and movement—and will need assistance to direct when and how to push. So even if a woman under epidural relief may be fully dilated she will not be active enough to move her body into positions that help move her baby down, nor is she able to use bodily techniques that help progress labour naturally. This is when an assisted delivery with the use of forceps or ventouse may be necessary to aid the baby’s delivery.

The 2011 Cochrane Review provides some data that statically demonstrates some potential downsides to having an epidural. These outcomes from 38 studies involving 9,658 women showed that epidural analgesia was associated with an:

• Increased risk of assisted vaginal birth
• Increased use of syntocin
• Increased risk of maternal hypotension (low blood pressure)
• Maternal fever

As with any type of medical intervention during labour there are benefits as well as potential risks and side effects. We discuss more of these considerations here and encourage you learn as much as you can in order to make well-informed choices.