What is an induction of labour?
Inducing labour, or starting the birth process by getting the cervix ready and/or starting labour contractions, is a process that is offered by midwives and doctors for many reasons in pregnancies where the baby's head is coming down first (not breech). They discuss these options to help come to shared decision-making regarding necessity, timing, outcomes, and different ways for induction. Inductions are offered when there are no labour contractions and there is not effective dilation of the cervix.
Sometimes, it may be so uncomfortable physically (back or hip pain, inability to sleep) that you request an induction. Other times, an induction is needed because mom or baby is getting sick. Conditions that warrant earlier or expedited delivery include:
Maternal reasons:
- Pre-eclampsia (high blood pressure that gets worse quickly and can increase risks for seizure of stroke)
- Cholestasis (slowed bile flow)
- Gestational diabetes
- Previous stillbirth
- Past your due date
- Parental choice (discomfort, childcare issues, anxiety)
- Birth parent is over 40 years old
- Water broke and labour contractions have not started for over 12 hours (increasing the risk for infection)
Baby reasons:
- Very large (macrosomic) baby
- Very small baby (growth restricted)
- Too little or too much amniotic fluid
- Not feeling baby move very much
Placental reasons:
- Poor blood flow to and from the baby (often related to a small baby or high blood pressure)
- Dysfunction (often with an older placenta past the due date or high blood pressure)
Cervical sweeps (a quick, slightly uncomfortable vaginal exam to check if you're dilating) offered by your care provider from weekly from week 38 onwards can help "ripen" or get your cervix ready. The cervix is at the bottom of your uterus or womb, and needs to open fully to 10 cm for vaginal delivery. This check if safe even if you are GBS positive and is done in your doctor midwife's office, or in triage.
Inductions of labour can be done in many ways. Your midwife or doctor will explain the options, risks, and benefits for you depending on your situation, and readiness of your cervix. Inductions are usually started when your cervix if closed, fingertip open, or less than 2 cm open. Sometimes a combination or techniques might be used. Sometimes one way doesn't work for one period while it works very well for another. Inductions take a long time because they are starting a process that didn't start on its own, and the timing is on top of the usual 14-20 hours of first time labour. All of the processes work to stimulate the hormones in your cervix to soften and bring on your oxytocin hormone to cause your uterus to contract over time.
Foley catheter or tube in your cervix. This 5-10 minute procedure involves a speculum (like during a pap smear) for the doctor to see your cervix. A small 3 cm balloon on the end of the tube is inflated with water above the cervix opening to help ripen the cervix. You may feel some mild cramps afterwards that may or may not kickstart labour in the hours to come. You may be offered the option to go home or to stay in hospital. This procedure may be combined with oxytocin (pitocin drip) depending on whether it is effective in bringing on labour.
Prostaglandin vaginal ribbon or gel. This hormone insert helps to soften and ripen the cervix. It leads to mild cramps and contractions and the start of labour in the next 6 to 12 to 24 hours.
Oral or vaginal misoprostol. This medication is given on a specific schedule in hospital to help with ripening the cervix and starting labour.
Breaking your water. Your water may break on its own or be broken by your midwife or doctor. This helps your body to bring on more hormones to continue the cramping and labour process. This can only be done once you are dilated at least 2-3 cm and the baby's head is low enough and engaged.
Oxytocin. This hormone is given in an iv tube in vein of your hand or arm. It is given gradually and labour cramps are usually felt in a couple hours. It can be turned off or turned down and the effects leave your body quickly.
