In this article on induction of labour we provide an overview, or summary, of what to expect during an induction.  If you know you are going to be induced, or would simply like to read more about this topic, please read our article Induction: Detail.

What is induction of labour?

Induction is starting labour artificially – rather than waiting for the mother to go into labour naturally. Interestingly no one knows what actually starts natural labour – although we know which hormones are involved in initiating labour, we do not know the triggers for the hormones to be produced in the first place.

The principle hormones are prostaglandins and oxytocin which can both be produced synthetically and be given to pregnant women to induce labour. Approximately 20% of women in New Zealand have their labours induced.

Why would I have my labour induced?

There are many reasons why women may be advised to have their labour induced or started before the body has gone into labour naturally. No medical interventions are without potential complications, however, so it is advisable to be patient and await natural events, unless you have been advised otherwise by an obstetrician. Each woman and each pregnancy must be considered individually to decide whether induction is the right option.

The most common medical reasons for induction are:

  • Overdue or post dates
  • Pre eclampsia
  • Reduced growth or reduced movements from the baby
  • Diabetes
  • Spontaneous rupture of membranes, prior to going into labour
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What does induction of labour involve?

There are 3 main parts to induction of labour:

Prostaglandins to induce labour

Prior to the onset of labour your cervix is closed and hard and 2-3cm long. The early pains – which are often irregular and less painful – soften and thin the cervix. This process is stimulated by the hormone prostaglandin, which the body produces when labour begins naturally.

If you are being induced this hormone will be given to you to soften your cervix, if it is hard and closed, in gel or pessary (tablet) form into your vagina.

Prostaglandins will usually cause ‘period type’ pains in the back or lower abdomen and these result in your cervix opening a little, to enable the midwife or doctor to break your waters. This stage of ‘early labour’ can be tiring and painful – showers and warm baths and massage may be helpful and if necessary the hospital midwives will give you pain relief, such as paracetamol. Ensure that you rest at this time and eat small nutritious meals to keep your energy up for labour.

Breaking the waters as part of induction

The membranes create a ‘balloon of water’ which creates a sterile environment and protects the baby inside. If the membranes have a hole in them, some of the fluid will drain out, bringing the baby’s head right down onto the cervix. This causes stronger contractions. So your LMC may use a small instrument like a crochet hook to make a hole in the membranes; this can also be called ‘rupturing your membranes’, ‘artificial rupture of membranes’ or ‘ARM’.

Oxytocin drip

Labour contractions happen as a result of the hormone oxytocin. This is produced by the body in normal/ spontaneous labour. It can also be produced synthetically to produce labour pains and this is called ‘syntocinon’. This is given via a drip into the hand or arm.

Sometimes induction of labour can be slow and painful, and being attached to a drip and a monitor does reduce your ability to move around and get comfortable. Your lead maternity carer will advise you about pain relief – many women who are induced have an epidural, as the process can be very long and tiring.

What are the risks and complications of induction?

Labour is essentially a natural process and any interventions or interferences with that normal process carry risk of complications.

There is a risk that the baby will not react well to the hormones or having the waters broken and that they will show signs of distress (lack of oxygen) through their heart rate or by moving their bowels inside you.

Once labour has been initiated – particularly once the waters have broken – it is not usually safe to stop the procedure, due to risk of infection to mother and baby. Failed induction will usually result in a caesarean section.

If your waters are broken before baby’s head has moved down in your pelvis, the cord may come down into the vagina – and this will affect baby’s blood supply. Once again the result would probably be a caesarean section.

What can I do to prevent induction of labour?

Try to avoid induction of labour if you can – but life is a balance of risks and some medical conditions in pregnancy carry a greater risk than induction of labour, in which case this will be the best option for you at that time.

Ask about having a membrane sweep prior to induction of labour. This is a vaginal examination that aims to stimulate your body to produce its own prostaglandins and therefore start labour naturally. It can be uncomfortable, but it lessens your chance of needing induction of labour.

We all get fed up towards the end of pregnancy due to tiredness and discomfort. Seek help of friends / family / whanau at this time and try to stay patient and rested to allow your body to go into labour naturally… just like animals we will only go into labour when we feel safe and secure!

If you would like more detailed information on this topic, please read our article Induction: Detail.

Helpful Induction Websites


This UK website contains factual information on the process of induction of labour and a section on membrane sweeping.

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Paula Skelton is a qualified NZ nurse and midwife, a midwifery & childbirth educator and the mum of three lovely girls.

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What percentage of inductions in NZ result in c-sections?

Kathy Fray

I don’t know NZ has statistics on rates of Inductions resulting in C-sections. However I can explain that it is not so much the induction process that increases surgical delivery rates, but more so the induction consequences. For example, if a cervix is wonderfully ripe, and the only Induction process required is the rupture of the waters to successfully establish labour, then this has good chances of resulting in a normal vaginal delivery. If however, the woman’s cervix requires several days of prostaglandin gel to ripen it ready for rupturing the membranes. Then after the waters are broken, she requires IV syntocinon… Read more »

Rochelle Gribble

Thanks Kathy 🙂

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