Usually IV oxytocin is given in combination with breaking the waters (or an 'ARM'). This can optimise the effectiveness of the drug. Ideally the woman's cervix is favourable, enabling this procedure to be performed easily (and comfortably). If the cervix is very firm, closed and posterior (or hard for the caregiver to reach), it can be near impossible to rupture the woman's membranes (without causing her significant discomfort).

Sometimes the ARM is delayed until the oxytocin has had some time to run for a while. This may allow for some early contractions to dilate the cervix a little. (However, it is possible that the cervix remains unchanged, even with hours of high doses of oxytocin, so most caregivers will try to break the waters at the beginning).

There is generally a 'maximum dose' of oxytocin that should be given. Maximum doses for first time mothers are usually higher than maximum doses for mothers having their second or subsequent baby. If you reach the maximum dose (and you are on this for a couple of hours with only mild contractions) and / or the cervix is not dilating, then the induction is regarded as being unsuccessful (or a 'failed induction'). The decision would then be made to perform a Caesarean operation.

An unsuccessful induction is more likely if you are less then 41 weeks pregnant, this is your first baby or your cervix is unripe. Hopefully if the cervix were unripe, your caregiver would have implemented some alternative methods to make the cervix more favourable, or ripe, before the oxytocin was started. This could include a Foley's catheter or one or two doses of prostaglandins, before breaking the waters and / or having an oxytocin drip.


Advantages. IV oxytocin (or 'Syntocinon') can be used alone (with breaking the waters) and can tend to shorten the labour. Oxytocin may be the next option if prostaglandins fail to induce the labour. It is also an option if the woman is allergic to the prostaglandin medication.