Labour induction: why it is done and what each method involves
In this article
Labour induction, or induction of labour, means starting labour with medical help instead of waiting for it to begin on its own. KKH says the aim is a vaginal birth. The usual reasons are a pregnancy that has gone past the due date, a health condition such as gestational diabetes or high blood pressure, or a concern about your baby, like poor growth. Methods range from a membrane sweep to a hormone drip.
| Common reasons | Overdue, diabetes, high blood pressure, baby not growing well |
|---|---|
| First step | A vaginal examination to assess your cervix |
| Methods | Sweep, pessary, balloon, breaking the waters, oxytocin drip |
| Vaginal birth after induction | About 6 to 7 in 10, SGH says |
| Where at KKH | Obstetric Monitoring Unit or Delivery Suite |
Why your doctor may suggest an induction
KKH names three common reasons: a medical condition in the mother, such as gestational diabetes or hypertension; a baby at risk, for example from growth restriction; and an overdue pregnancy. SGH adds waters that break before labour after 34 weeks, and conditions such as chronic hypertension, diabetes or autoimmune disease.
The NHS offers induction if labour has not started by 41 weeks, because the risk of stillbirth and problems for the baby rises after that. Ask your gynae which week they use. If your waters break after 37 weeks and you carry group B strep, KKH offers induction straight away.
How labour is induced at KKH
Your doctor first checks your cervix with a vaginal examination, then picks a method. ACOG describes the Bishop score, a rating from 0 to 13, that doctors may use; under 6 means the cervix may not be ready. The methods KKH uses:
- Membrane sweep: a gloved finger sweeps around the cervix. KKH says it makes labour more likely to start in the next 48 hours, and can cause some discomfort and a small bleed.
- Prostaglandin pessary: a hormone that softens the cervix, released over 24 hours from a single pessary with a retrieval tape, or over 12 to 24 hours from a pessary that may need repeating.
- Cervical ripening balloon: a catheter with a saline-filled balloon that stretches the cervix, left in for about 12 hours.
- Breaking the waters: once the cervix has started to open, a thin sterile plastic hook breaks the water bag.
- Oxytocin drip: if contractions have not started, a hormone drip makes them regular and strong.
ACOG calls the pessary and balloon stages ripening the cervix: helping it soften and thin out, the change your midwife records as effacement, so that it can open.
What an induced labour feels like
SGH says induced labour can be longer and more painful than labour that starts on its own. The NHS says being induced does not limit your pain relief, so an epidural is still available. It also says you are more likely to need forceps or a vacuum cup.
KKH lists two main risks. The cervix may fail to soften, in which case you may be offered another method or a caesarean. And a small number of women are very sensitive to the medicine, so the womb contracts too often or too strongly. SGH says induction ends in a vaginal birth, normal or assisted, in about 6 to 7 out of 10 pregnancies.
Getting ready for your induction at KKH
Planned inductions at KKH are booked through the outpatient clinic. You go to the Obstetric Monitoring Unit, a 10-bed area in Ward 32 with central fetal monitoring, or straight to the Delivery Suite. KKH asks you to eat a meal before your appointment and bring your antenatal appointment booklet, identity cards for you and your husband, and the inpatient admission authorisation form.
Once you are in labour, you move to the Delivery Suite until your baby is born. Our induction of labour guide has more on each method.
Frequently asked questions
How long does labour induction take?
It varies, KKH says, because every woman responds differently. Softening the cervix alone can take 12 to 24 hours with a pessary, or about 12 hours with a balloon, before your waters are broken or a drip is started.
Is induced labour more painful?
It can be. SGH says induced labour can be longer and more painful than labour that starts naturally, and the NHS says all the usual pain relief, including an epidural, is still open to you.
Can I say no to an induction?
The NHS says it is your choice, and that if you go past 42 weeks without induction you should be offered extra monitoring of your baby. Ask your gynae to explain the reason for your induction and what waiting would mean.
What happens if the induction does not work?
KKH says you may be offered a different method, or a caesarean if the cervix does not soften. The NHS says waiting a few hours and reassessing is sometimes an option too.
Related terms
- Effacement: The thinning and shortening of your cervix before and during labour, given as a percentage from 0 to 100.
- Dilation: How far your cervix has opened in labour, measured in centimetres from closed to 10cm.
- Rupture of Membranes (Water Breaking): When the bag of fluid around your baby breaks and leaks out through the vagina, as a gush or a trickle.
- Epidural: Labour pain relief given through a fine tube in your lower back by an anaesthetist, numbing the womb and birth canal.
- Gestational Diabetes: High blood sugar that starts in pregnancy. Singapore screens every mum-to-be with a glucose test at 24 to 28 weeks.
- C-section (Caesarean Section): An operation to deliver your baby through a cut in your tummy and womb, planned ahead or done in labour.
