Induction is the artificial stimulation of uterine contractions, to start labour before it starts spontaneously.
What is offered, and exactly how and when it happens, may vary. Please check at your local hospital.
This guide is intended for the United Kingdom only.
Reasons for Induction
Induction is normally only used if pregnancy is prolonged, or if you have medical reasons to deliver your baby early, eg. high blood pressure. Many hospitals have a policy of when to offer you induction, eg. due date (40 weeks) + 10 days. It is your choice whether to accept.
A pregnancy may end in childbirth quite normally anywhere from 38-42 weeks (some sources suggest 37 weeks). Your due date is simply a mid-point. You aren't late when you're past your date!
First babies of white mothers are most commonly born around 41 weeks! Black, Asian mums – around 40 weeks. After 42 weeks of pregnancy, and only after that, there is a small increase in risk for the baby.
If you choose to postpone or refuse induction, you should be offered extra checks especially after 42 weeks. This is current NICE (government) policy.
The main ‘risk’ of induction is the sudden onset of labour, which you may find hard to handle. Extra pain relief may be helpful.
Methods of induction
1. stretch and sweep – membrane sweep
2. prostaglandin gel or pessaries
3. breaking of waters – artificial rupture of the membranes – ARM
4. drip – synthetic oxytocin – syntocinon drip
Stretch and sweep (membrane sweep)
This can be done by a midwife at the clinic or surgery. During a vaginal examination the cervix is stretched with a finger and slightly detached from the membranes surrounding the waters and baby. This can stimulate hormones (prostaglandins, oxytocin) and contractions.
Recent evidence suggests 3 sweeps on 3 successive days has good results, though not guaranteed. Probably uncomfortable, but does not take long.
Works well in women who have already had children.
Hormones which soften and prepare the cervix, and may trigger labour.
The procedure may be like this:
DAY 1. Come into hospital, have a vaginal examination to assess readiness of cervix; if suitable, prostaglandins are applied either as a gel or pessaries (a lozenge inserted in vagina).
Electronic Foetal Monitor (EFM) will be used to check the baby. Partner cannot stay the night as this is not yet established labour and you will not be on the labour ward.
DAY 2. You may have experienced some contractions, some women react immediately. But labour may not start, so another dose can be given. You may have three or four doses, at intervals of 6-8 hours. You need to wait 6 hours after each dose in case there is a reaction.
If nothing happens after this, maybe you and the baby are not ready, you may be sent home for a while.
Alternatively, other methods may be suggested.
(If the baby becomes distressed, you will be advised of your options, you may need a Caesarean Section.)
Breaking the Waters
(Artificial Rupture of Membranes = ARM)
Sometimes your waters naturally break before labour starts. Labour does usually begin within 24-48 hours if you are full term. Hospitals will have a policy on how long they advise waiting, before taking you into hospital: ask your local midwife.
ARM is done in hospital. A vaginal examination is done to assess the cervix. If it is already softening and dilating a bit, but everything is very slow or has stopped, ARM may be offered. Your waters are broken using an amni-hook, which looks like a long crochet hook. This allows the baby’s head to come down more firmly onto the cervix, stimulating it. Labour may suddenly become a lot more active.
Hospital staff prefer you not to leave the hospital, and prefer to see the baby born within 24 hours of ARM. There is a small risk of infection. EFM* will monitor your contractions, and the baby.
If after 2-4 hours there is no change, you may be offered a syntocinon drip.
Drip - Syntocinon
This is synthetic oxytocin, given intravenously. It can help start a labour (induction), or speed up a slow labour (augmentation). Syntocinon is much stronger than natural oxytocin, and contractions tend to be suddenly much more painful.
You will be continuously monitored using EFM* and if the cervix does not dilate steadily, the possibility of a Caesarean will be discussed.
* Electronic Fetal Monitoring – belts connected to a screen, monitors baby’s heart and mum’s contractions.