Emma Armstrong
what is amniotomy/ARM
Breaking the waters (amniotomy/ARM)
Sometimes the use of prostaglandin or a mechanical method is enough to bring on effective labour contractions and nothing further is needed. If not, once the cervix is slightly dilated, midwives and doctors will often suggest breaking the waters to try to start or strengthen the contractions. This is sometimes referred to as an amniotomy or artificial rupture of the membranes (ARM).
It is a common experience that contractions become a lot stronger after the waters break naturally during labour. This may be because it allows the baby’s head to move down and press on the lower part of the womb, which sends signals to the brain telling it to produce more oxytocin.
ARM is intended to mimic this process, but there is no direct evidence to show whether ARM following a medical induction is helpful or does more harm than good.
Despite its widespread use, there is no direct evidence that ARM helps progress into active labour following induction.
There are some potential risks which include pain, increased stress on mother and baby, infection and possibly the rare risk of cord prolapse.