If breaking the waters does not accelerate (or intensify) the labour, then you may need to have an oxytocin drip (Syntocinon) in the delivery suite. This will normally involve having the baby's heart rate continuously monitored. Other options for medical augmentation are not appropriate at this stage of the labour (as prostaglandins are used for induction when the waters are not broken). If your labour still does not progress with the oxytocin drip, (or the baby becomes distressed) then you may need a Caesarean operation (if the cervix is not fully open or dilated), or a forceps or ventouse delivery if the cervix is fully dilated.
Advantages of an ARM.
An ARM is a mechanical form of augmentation that can be performed by a midwife, or doctor, in any birth setting. (For women who are labouring in a birth centre (or at home) it may be the only option before transferring to the delivery suite.) An ARM has the advantage of fewer side effects than oxytocin, and does not require continuous monitoring (unless the waters are heavily stained with meconium, indicating the baby may have been in distress at some stage).
Research to date shows that performing a routine ARM early in the labour can shorten the labour from between 60 - 120 minutes and reduce the likelihood of needing an oxytocin drip.
Disadvantages of an ARM.
An ARM done when the woman is between 3 to 9 cms dilated can rapidly intensify her labour. This can sometimes be difficult to deal with, after having little or no contractions for a while, and then suddenly being in established labour again. Having an ARM may make the woman more inclined to have pain relief earlier. If an ARM is performed close to when the cervix is fully dilated, the woman will probably soon feel like she needs to push (which may be a positive outcome).