The hows and whys of induction

There are several reasons why your medical team may suggest giving nature a medicinal helping hand

When doctors or midwives medically intervene to kick-start labour, the process is known as induction. Your doctor or midwife will suggest induction if he or she believes that it would be better for either your or your baby’s health for the baby to be born without waiting for natural labour to start.

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There are numerous reasons why an induction may be necessary or recommended, the most common of which is going past your due date to the extent that doctors are concerned for the baby’s health: After you go beyond full term the placenta may start to deteriorate, and so provide inadequate oxygen and support for your baby. If you do go over a week beyond your due date then your doctor will monitor this to ensure the baby isn’t at risk. Mothers with severe health conditions that pose a risk as pregnancy continues – such as pre-eclampsia and diabetes with complications – are usually recommended planned inductions. An induction may be suggested if your waters have broken more than 24 hours before contractions start of their own accord because the risk of infection is greater when your baby is no longer protected by the bag of waters. Other grounds for a suggested induction include you have a mild health condition that may affect the course of labour, or if your baby is particularly large.

Medical reasons aside, an induction may also be suggested for reasons of convenience.

What happens
There are different ways of activating labour, depending on urgency and how prepared your body already is for labour, for example how ripe your cervix is.

  • Pessaries – Prostaglandin gel is inserted into the vagina in the form of a pessary to ripen the cervix and stimulate contractions. Prostaglandin is a hormone naturally produced by the uterus lining for both those purposes. Once the gel is inserted you will be recommended to rest in bed for a while.

The prostaglandin pessaries are inserted every six hours and the number you receive will depend on whether it was necessary to help ripen the cervix before contractions and how long that process takes.

For most women contractions will start once the cervix is ripe, though in some cases it may be necessary to take further induction measures such as artificially breaking your waters or an oxytocin drip (see below).

After pessaries are inserted your baby’s heartbeat will probably be monitored with a CTG to check that the baby isn’t adversely affected by the induction, particularly if the prostaglandin provokes strong and frequent contractions.

  • Breaking waters (artificial rupture of membranes) – If your cervix is ripe and dilation has begun then your midwife or doctor may recommend breaking your waters for you to help things along. This acts to stimulate labour because the rupturing of the membranes prompts the uterus lining to release prostaglandin.

To break your waters the doctor or midwife insets a thin instrument with a hook through the cervix to puncture the membrane. The procedure will probably involve a bit of discomfort. If breaking the waters doesn’t lead to contractions within a few hours then you will probably be given an oxytocin drip to stimulate labour.

  • Oxytocin / Syntocinon drip – Usually used once the cervix is ripe and dilation has begun, and when pessaries and breaking the waters haven’t succeeded in establishing labour – or simply to speed up a slow labour. A synthetic version of oxytocin, a hormone naturally produced by both mother and baby to (among other things) stimulate the uterus to contract, is administered intravenously.

The hormone is delivered in gradually increasing amounts in imitation of the way the hormone oxytocin is released naturally. However, in some cases the hormone may lead to over-stimulation of the uterus, reducing the amount of oxygen reaching the placenta and you will be monitored to check for fetal distress. If fetal distress or overly strong contractions result from the oxytocin then the midwife of doctor will either decrease or stop the drip.

What you should be aware of
While induction is usually successful, it may lead to stronger, more sudden and more painful contractions and a longer labour, which will increase the likelihood of you needing pain-killing drugs. Very strong contractions may also decrease the supply of oxygen available to your baby and so raise the risk of fetal distress, which is why CTG monitoring is often used alongside the various forms of induction.

With an increase in the likelihood of fetal distress comes a corresponding increase in your chances of further intervention, such as ventouse or forceps delivery and caesarian section. Such further intervention is more likely to be necessary if your induction is based on medical reasons, such as pre-eclampsia.

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Given the potential risks of induction, you might want to discuss the grounds for induction with your care givers if it is suggested to you, and if the recommendation isn’t based on a serious health condition, consider trying natural ways of prompting labour before trying medical intervention.

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