Induction of labour: methods, reasons and what to expect
Induction of labour means using medical methods to start labour artificially rather than waiting for it to begin on its own. It is a routine procedure on NHS maternity units, and the decision to offer it is always based on a clinical assessment of what is safest for you and your baby. Understanding why induction might be recommended, what the process involves and how long it takes can help you feel prepared and able to ask good questions when the time comes.
Why induction of labour is recommended
The NHS and NICE guideline NG207 are clear that induction is offered when the risks of continuing the pregnancy outweigh the risks of inducing birth. It is not offered routinely without a clinical reason.
One of the most common reasons is going past 41 to 42 weeks of pregnancy. As a pregnancy continues beyond 42 weeks, the risk of stillbirth and other complications increases, and induction is typically offered to prevent this. Concerns about the baby's growth or reduced movement may also lead a team to recommend induction, as these can be signs that the placenta is no longer supporting the baby as well as it should.
Other reasons include pre-eclampsia, a condition involving high blood pressure and organ strain that can become serious if the pregnancy continues. Gestational diabetes with complications is another indication, as is the waters breaking (rupture of membranes) without contractions starting within a set window. Your midwife or obstetrician will explain the specific reason that applies in your case and discuss the timing and method that best fits your situation.
Methods used to induce labour
Induction is not a single procedure. It is usually a staged process, and the method used depends on how ready your cervix is. This readiness is sometimes described using a scoring system called the Bishop score, which assesses the position, softness, length, dilation and descent of the cervix.
Membrane sweep
A membrane sweep, sometimes called a stretch and sweep, is often offered as a first step before formal induction begins. During an internal examination, a midwife or doctor sweeps a finger around the cervix to separate the membranes from the cervical wall. This releases hormones called prostaglandins, which can encourage labour to begin naturally. A sweep is usually offered from 38 to 40 weeks in certain pregnancies and at 40 to 41 weeks in routine ones. It can cause cramping and some spotting and does not always work, but it is the least invasive approach and may avoid the need for further intervention.
Prostaglandins
If a sweep has not brought on labour or is not appropriate, the next step is usually prostaglandins. These are hormone-like substances that help soften and open the cervix, a process called cervical ripening. They are given as a pessary or gel inserted into the vagina, or as a small tablet. The pessary or gel may be given once or repeated after a set period, depending on how your body responds. During this stage you are monitored but often able to move around and eat normally. Prostaglandins can cause cramping and backache. If they successfully ripen the cervix and labour begins, no further intervention may be needed. If the cervix has ripened but contractions have not started, the next step is usually an artificial rupture of membranes or an oxytocin drip.
Artificial rupture of membranes (amniotomy)
Once the cervix is sufficiently open, a midwife or doctor may break the waters artificially using a small instrument to make a hole in the membrane. This is called an amniotomy. It is performed during an internal examination and feels similar to a routine examination, though it may cause a gush of warm fluid. Breaking the waters can encourage contractions to start or become stronger. It is often used alongside oxytocin if contractions need further help to establish.
Oxytocin drip
Oxytocin is the hormone your body produces naturally to cause contractions. During induction, a synthetic version called Syntocinon is given through a drip into a vein in your arm. The dose is increased gradually until contractions are regular and effective. Because oxytocin can make contractions come more quickly and intensely than in spontaneous labour, continuous monitoring of the baby's heart rate using a CTG machine is required throughout. This means you will need to stay near the monitor, which limits mobility, though wireless monitoring is available in some units. The oxytocin drip is adjusted throughout labour in response to how contractions and the baby are progressing.
What to expect during the induction process
Induction typically takes place in a hospital maternity unit, and you may be admitted to an antenatal ward for the early stages. The timeline varies considerably from person to person. If your cervix needs ripening with prostaglandins first, the process may take a day or more before active labour is established. If your cervix is already favourable, labour may begin relatively quickly after the waters are broken or the oxytocin drip is started.
All pain relief options available in spontaneous labour, including gas and air, opioid injections and epidural, are also available during induction. Because contractions with an oxytocin drip can be more intense and come more quickly, some people find they want stronger pain relief than they had originally planned. This is entirely reasonable and something you can request at any point. Your birth partner is usually able to be with you once you are in the labour room, though visiting may be more restricted on the antenatal ward.
If induction does not lead to labour after a reasonable attempt, or if concerns arise about how the baby is coping during the process, your team may recommend a caesarean section. This is not a failure of induction; it is a clinical response to what is safest for you and your baby at that point.
Frequently asked questions
Why is induction of labour offered?
Induction is offered when continuing the pregnancy poses more risk than inducing birth. Common reasons include going past 41 to 42 weeks, concerns about the baby growth or movement, pre-eclampsia, gestational diabetes with complications, and waters breaking without contractions starting.
What does induced labour feel like?
The early stages of induction (prostaglandin, membrane sweep) may cause cramping and backache. Once the oxytocin drip is started, contractions can come more quickly and intensely than in spontaneous labour. All pain relief options available in natural labour are also available during induction.
How long does induction take?
Induction can take anywhere from a few hours to a couple of days, depending on how ready the cervix is and how the body responds. If the cervix needs to ripen first with prostaglandins, the process is longer.
Can I decline induction of labour?
Yes. Induction is a recommendation based on clinical assessment, but it is your decision. You have the right to decline and discuss expectant management with monitoring. Your team will support you in making an informed decision.
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