Labour Induction
Labour induction is a medical procedure where healthcare professionals use medications or other methods to start contractions before they begin naturally, helping to bring about childbirth when continuing pregnancy carries greater risks than delivering the baby.
Table of contents
- What is labour induction?
- Reasons for inducing labour
- When labour induction happens
- Methods used to induce labour
- What to expect during induction
- Possible risks and complications
- When induction does not work
What is labour induction?
Labour induction means getting the uterus (the organ where a baby grows during pregnancy) to contract before labour begins on its own.[1] The main reason healthcare professionals suggest labour induction is concern for the health of the baby or the pregnant person.[1] When a healthcare professional suggests labour induction, it is most often because the benefits are greater than the risks.[1]
Labour induction is a common medical procedure. In high-income countries, approximately one in four babies is born following labour induction.[5] In the United States, induced births make up about 23 to 25 percent of all births.[7][13] The rates of labour induction have nearly doubled since 1990.[5]
It is typically best to allow labour to begin on its own when possible.[7] However, labour induction is indicated when the outcomes for the baby, the mother, or both are expected to be better than with waiting for spontaneous labour to start.[5]
Reasons for inducing labour
Healthcare professionals may recommend labour induction for various medical reasons. To decide if you need labour induction, a healthcare professional looks at several factors, including your health and the baby’s health, gestational age (how far along the pregnancy is), weight estimate, size and position in the uterus.[1]
Medical conditions affecting the pregnant person
Labour induction may be recommended if you have certain health conditions, including:[1][2]
- Diabetes (high blood sugar levels). This can be diabetes that came on during pregnancy, called gestational diabetes, or diabetes that was present before pregnancy. If you use medicine for your diabetes, delivery is suggested by 39 weeks. Sometimes delivery may be earlier if diabetes is not well controlled.
- High blood pressure or preeclampsia (a serious condition involving high blood pressure and other symptoms during pregnancy)
- Other medical conditions such as kidney disease, heart disease or obesity
- An infection in the uterus called chorioamnionitis
Pregnancy-related reasons
Other reasons for labour induction relate to how the pregnancy is progressing:[1][2][3]
- Labour that has not started on its own one or two weeks after the due date. At 42 weeks from the day of the last period, this is called a postterm pregnancy.
- Labour that does not begin after the water breaks. This is called premature rupture of membranes (PROM). If your waters break more than 24 hours before labour starts, there is an increased risk of infection to you and your baby.
- Problems with the baby, such as poor growth, called fetal growth restriction
- Too little amniotic fluid (the protective liquid surrounding the baby) around the baby, called oligohydramnios
- Problems with the placenta (the organ that provides oxygen and nutrients to the baby), such as the placenta peeling away from the inner wall of the uterus, called placental abruption
- History of stillbirth or rapid delivery
Elective induction
When you choose labour induction and you and your baby are healthy, it is called elective induction.[11] For example, labour may be induced at your request for reasons such as physical discomfort, a history of quick labour, or living far away from the hospital.[11]
New research suggests that induction for healthy women at 39 weeks in their first full-term pregnancies may reduce the risk of cesarean birth (surgical delivery through a cut in the abdomen and uterus).[4] Healthy women whose labour is induced at 39 weeks may have lower rates of preeclampsia and gestational hypertension than women who do not have induction at 39 weeks.[4] However, elective induction should not be done before 39 weeks of pregnancy.[4][11]
When labour induction happens
The timing of labour induction varies depending on the health of your pregnancy. Pregnancy care providers weigh the risks and benefits of inducing labour. Ideally, they wait until 39 weeks of pregnancy to induce labour.[2] When a woman and her baby are healthy, induction should not be done before 39 weeks. Babies born at or after 39 weeks have the best chance at healthy outcomes compared with babies born before 39 weeks.[4]
However, if the baby’s health is at risk, inducing labour before 39 weeks may be the safest option.[2] When the health of a woman or her baby is at risk, induction before 39 weeks may be recommended.[4]
Induction will usually be planned in advance. You will be able to discuss the advantages and disadvantages with your doctor and midwife, and find out why they think your labour should be induced.[3] It is your choice whether to have your labour induced or not.[3]
Methods used to induce labour
There are several ways pregnancy care providers induce labour. Your provider will examine you and check your cervix (the opening to the uterus) before deciding how to proceed with inducing labour.[2] Throughout a labour induction, your provider monitors the baby to make sure it is tolerating labour well.[2]
Preparing the cervix
Before labour can progress, the cervix needs to be ready. The cervix begins to soften (ripen), thin out (efface), and open (dilate) as it prepares for labour and delivery.[11] If your cervix is hard and closed, the first step in inducing labour is to ripen your cervix.[2]
Healthcare professionals use the Bishop score to check if your cervix is ready for labour. With this scoring system, a number ranging from 0 to 13 is given to rate the condition of the cervix. A Bishop score of less than 6 means that your cervix may not be ready for labour.[11]
Methods to ripen the cervix include:[2][3][8]
- Giving you medication to soften, thin and open your cervix to prepare it for childbirth. Hormones such as prostaglandins can be placed inside your vagina using a vaginal tablet (pessary) or a gel, or given as tablets that you swallow.
- Using a balloon catheter (a narrow tube with a small balloon on the end) or osmotic dilator (a type of sponge) to widen your cervix. The doctor inserts it into the cervix and inflates the balloon, which helps the cervix open.
- Stripping (or sweeping) the membranes. Your provider passes a gloved finger over the membranes connecting the amniotic sac (which houses the baby and amniotic fluid) from the wall of the uterus. This triggers the body to release prostaglandin, which may bring on contractions and help prepare the cervix for delivery.
Starting contractions
Once the cervix is ready, or if it is already starting to ripen, healthcare providers may use methods to start contractions:[2][4]
- Breaking your water, also called amniotomy or artificial rupture of membranes. The doctor makes a small hole in the amniotic sac during a vaginal exam using a small plastic hook to break the membranes.
- Giving you medication that causes contractions. Oxytocin is given through a vein (intravenously), usually after the cervix softens. It causes the uterus to contract.
What to expect during induction
Induction is always carried out in a hospital maternity unit. You will be looked after by midwives and doctors will be available if you need their help.[3]
It depends on the induction method your provider uses and how soft (or ripe) your cervix is. Before inducing labour, your provider will examine your cervix to see how ready it is.[2]
It usually takes many hours for these treatments to start working. You will usually stay in the hospital maternity unit, though you may be able to go home in some cases.[3] With the use of medication to induce labour, active labour can start quickly, but it truly depends on each person and how their body responds to the medication. For some people, labour starts quickly, and for some, it can take hours to days to begin active labour. Typically, people should expect at least 24 hours for their induction.[7]
Pain during induced labour
Induced labour is usually more painful than labour that starts on its own.[3][12] However, your pain relief options during labour are not restricted by being induced. You should have access to all the pain relief options usually available, such as an epidural (pain relief injected into the space around the spinal nerves in the lower back) or water birth.[3]
Possible risks and complications
Labour induction can have some risks and potential complications. If you are induced, you are more likely to have an assisted delivery, where forceps or ventouse suction (a vacuum device) are used to help the baby out.[3][12]
If you need to be induced, it may affect where you can give birth. You may need to stay in hospital for longer and have more examinations.[3][12]
Some conditions may make a vaginal delivery unsafe for you or your baby, such as placenta previa (the placenta covers the opening of the uterus), the baby lying sideways in the uterus or in a breech presentation, prolapsed umbilical cord (the cord has dropped down in the vagina ahead of the baby), active genital herpes infection, or some types of previous uterine surgery. In these situations, you may need a cesarean birth to protect the health of you and your baby.[11]
When induction does not work
Induction is not always successful, and labour may not start.[3][12] A failed induction of labour may happen if the labour induction process does not turn into active labour within 24 hours or more.[7]
If your labour does not progress, and if you and your baby are doing well after attempting induction, you may be sent home. You can schedule another appointment to try induction again. If your labour starts, you should go back to the hospital. If you or your baby are not doing well after attempting induction, a cesarean delivery may be needed.[4]
Your healthcare professional and midwife will assess your condition and your baby’s wellbeing. You may be offered another method of induction or a cesarean section.[3][12]
