When to Induce labour, Benefits, Risks, and Options
This information is to help you and your family make a choice about the induction of labour and to answer some of the questions you may have.
What is induced labour?
In most pregnancies, labour starts naturally between 37 and 42 weeks, leading to the birth of the baby. When labour starts, a number of changes take place in the body:
• The cervix (neck of the womb) softens and shortens
• The fluid-filled membrane sac surrounding your baby tears ("your waters break")
• The cervix dilates (opens)
• The womb contracts to push your baby out.
Labour is said to be "induced" when doctors and midwives encourage the labour process to start artificially.
When to induce labour?
Approximately one-fifth of women have an induction of labour. The most common reasons are:
• The woman has specific health concerns (such as diabetes or high blood pressure)
• The baby is not well or is distressed
• The pregnancy has gone longer than 41 weeks (prolonged pregnancy)
• The waters have already broken, but the labour contractions have not started naturally.
A labour induction is recommended when it is considered that your health and/or your baby's health will benefit.
Making your choice about induced labour
Everyone has the right to be fully informed and share in healthcare decision-making. Before you decide induction, your doctor or midwife will explain:
• Why an induction has been recommended for you, and the potential benefits
• The potential risks with continuing your pregnancy until labour starts naturally
• Potential risks with having an induction of labour
• The procedures and care that are involved during induction of labour.
Some women will choose "to wait and see" whether natural labour will start. However, it is important that you are aware of the risks of both options so that you can decide what is best for you. The information outlined below may also help to inform your decision.
How to induce labour?
Before starting the induction, your doctor or midwife will assess your cervix. This examination takes only a few minutes, but some women may experience discomfort. Based on this assessment, your doctor or midwife will recommend the most suitable method of induction as follows:
Induction of labour methods
1. If the cervix is soft and open, and the waters have already broken, the method of induction used is Oxytocin.
Oxytocin is the hormone that causes contractions. A synthetic version of Oxytocin is given to women when contractions don't start naturally. Oxytocin is given through a drip and enters a vein in the arm. Once contractions begin, the rate of the drip is adjusted so that contractions occur regularly until your baby is born. This process can take several hours. Your baby's heart rate will be monitored throughout labour using a CTG machine.
2. If the cervix is soft and open, but the waters have not broken, the method of induction used is ARM (and Oxytocin)
If your waters have not broken, a procedure called an "Artificial Rupture of Membranes" or "ARM" may be recommended. This is when your midwife or your doctor makes a hole in your membrane sac to release the fluids inside. This procedure is done through your vagina using a small instrument. Sometimes releasing the waters is enough to "get things going", and labour will commence. However, most women will also require the Oxytocin drug as well (described above) to start the contractions.
3. If the cervix is not soft and open and the waters have not broken, the method of induction used is Prostaglandin or cervical ripening balloon catheter (and ARM and Ocytocin, if needed).
Prostaglandin is a naturally occurring hormone that prepares your body for labour. A synthetic version has been developed to mimic the effect of the hormone. This is inserted into your vagina, usually in the form of a gel. When the prostaglandin is in place, you will be advised to lie down and rest for at least 30 minutes. During this time, the midwives will continue to listen to your baby's heart and check that you're not having a reaction to the drug. If everything is going well for both you and your baby, you may be discharged home and advised to return to the hospital later that day for another examination. You should return to the hospital immediately if you experience any of the following:
• Regular painful contractions 5 mins apart for your first baby or 10 mins apart for subsequent babies.
• Your membranes rupture (your waters break) spontaneously
• Your baby seems to be moving less
• You have vaginal bleeding.
When the prostaglandin takes effect, your cervix will soften and open. This may require one, two, or three doses (given every six to eight hours). When the cervix is soft and open, your body is prepared for labour. The next steps will vary from woman to woman - some might require an ARM to "break their waters", whereas this might happen naturally for other women. Some women might require Oxytocin to stimulate the contractions.
Prostaglandin does not suit all women, and there will be circumstances in which your doctor may recommend using a cervical ripening balloon catheter. This catheter is inserted into your cervix, and the balloons are inflated with saline, thus applying pressure to the cervix. The pressure should soften and open your cervix, thereby preparing your body for labour.
When the catheter is in place, you will need to stay in the hospital but you will be able to move around normally. Fifteen hours after the catheter has been inserted or when the catheter falls out, you will be re-examined. During this time, the midwives will periodically check you and listen to your baby's heart. Please tell the midwives caring for you if:
• The catheter falls out
• You have regular painful contractions; 5 mins apart if this is your first baby or 10 mins apart for subsequent babies
• Your baby seems to be moving less
• You have vaginal bleeding
What happens next will vary from woman to woman; some might require an ARM to "break their waters", whereas this might happen naturally for other women. Some women might require Oxytocin to stimulate the contractions.
Risks of inducing labour
Before deciding to induce labour, it is important to be aware of potential risks and disadvantages.
• Induction for reasons other than prolonged pregnancy may increase the chance of you having a caesarean section.
• Women who are induced are more likely to experience above-average blood loss after birth.
• In the event the birth suites are busy, your induction of labour may be delayed and the process of induction may take longer than one day.
What are the risks of Oxytocin during labour?
• Your ability to move around will be limited by the drip and the CTG monitor. Whilst it may be okay to stand up or sit down, it will not be possible to have a bath or move from room to room.
• Very occasionally Oxytocin can cause the uterus to contract too frequently which may affect the pattern of your baby's heartbeat. If this happens, you will be asked to lie on your left side, and the drip will be slowed to lessen the contractions. Another drug may be given to counteract the Oxytocin.
Risks of Artificial Rupture of Membranes
• The vaginal examination needed to perform this procedure may cause you some discomfort
• Although ARM is usually straightforward, it can increase the risk of cord collapse, bleeding and infection.
Risks of Prostaglandin
• Prostaglandin sometimes causes vaginal soreness. However, there is no evidence to suggest that labour induced with prostaglandin is any more painful than labour that has started naturally.
• A minority of women might experience some reactions to the prostaglandin - such as nausea, vomiting or diarrhoea, but this is rare. If you experience any reaction to the drug, you will stay in the hospital (rather than going home) so that you can be closely observed.
• Very occasionally, prostaglandin can cause the uterus to contract too much which may affect the pattern of your baby's heartbeat. If this happens, you will be asked to lie on your left side. You may be given medication to relax the uterus, and any prostaglandin gel remaining in your vagina may be removed.
What are the risks of cervical balloon induction
• The vaginal examination needed to perform this procedure may cause you some discomfort.
Dr Peter Jurcevic is the Parents You've Got This Obstetrician Expert. He specialises in high-risk obstetrics and natural birthing practices by providing highly personalised patient-centred care. Dr Peter presents at our Pregnancy and Birth Masterclasses.