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. This gives pain relief for around 2 hours, and if further pain relief is needed, it is given as an epidural.
Many women have a good experience with epidurals.
Sometimes the relief from pain can allow a woman to rest and relax sufficiently to go on and have a good birth experience. Often the decision to accept an epidural is made without an awareness of these, and other, significant risks to both mother and baby. Although the drugs used in epidurals are injected around the spinal cord, substantial amounts enter the mothers blood stream, and pass through the placenta into the baby's circulation. One of the most commonly recognised side effects is a drop in blood pressure. 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.