Induction of labour

Labour is a natural process that usually starts on its own. However, sometimes labour needs to be started artificially, this is called ‘induction of labour’. For a variety of different reasons, you may be offered an induction of labour. Your midwife or obstetrician will always discuss these interventions with you to ensure you fully understand the risks and benefits, enabling you to make an informed decision. Your consent will be gained prior to any procedure taking place.

Reasons to induce labour include (this list is not exhaustive):

• To avoid a pregnancy lasting longer than 42 weeks (“prolonged pregnancy”) - in these cases, induction is usually planned at 40 weeks plus 12 days gestation
• If your “waters” have broken but labour has not started
• Other medical reasons, for example raised blood pressure, diabetes or liver conditions
• Concerns about your baby’s health, for example, reduced growth on the ultrasound scan

At Warwick Hospital, we use a number of different methods to induce labour and the method you are offered will vary depending of a number of factors such as previous births, gestation, any medical conditions and your current pregnancy. Your midwife or obstetrician will explain the options available to you.

When you arrive on Swan Ward for your induction of labour, a midwife will undertake a full assessment of you and your baby. Your blood pressure, pulse, respirations and temperature will be taken and you will be asked for a urine sample. The midwife will check your baby by listening to the heartbeat, palpating your abdomen for baby’s position and monitoring your baby’s heart beat using a Cardio Tocograph (CTG) machine which will also be able to detect uterine activity such as Braxton Hicks or contractions. The midwife will then assess your cervix by undertaking a vaginal examination. Following this examination, the midwife will be able to discuss the most appropriate method of induction for you.

Often, induction of labour can be a long process and can take a number of days. This is because most women will need a combination of induction methods to get them in to established labour. Established labour is when the cervix is at least 4cm dilated with strong, regular contractions.

Dilapan is a mechanical way of inducing labour. This means there is no medication involved. Dilapan are small, thin rods that are inserted directly into the opening of your cervix. These are inserted by a midwife or obstetrician during a speculum examination. It is normal to have 3 to 5 rods inserted. Over a period of 12 to 24 hours, the Dilapan expands and physically opens the cervix. Once the Dilapan has had time to work the midwife will remove the rods and perform a vaginal examination to assess your cervix. Dilapan does not change the length or position of your cervix and it typically does not cause any contractions. Dilapan is used to open your cervix enough to allow the midwife to break your waters, also referred to as an Artificial Rupture of Membranes (ARM).

Foley catheter, also known as a cervical balloon catheter, is a mechanical method used for induction of labour.  It is a soft silicone tube which is inserted into the cervix. The catheter has a balloon near the tip. Once in place, the balloon is filled with sterile saline. The catheter remains in position for up to 18-24 hours, exerting gentle pressure on the cervix to dilate, with the aim to break your waters.

The tablet will be inserted into your vagina during a vaginal examination. It contains a hormone called prostaglandin which is released slowly and aids to ‘prime’ the cervix. It helps to soften your cervix and stimulate your uterus to tighten. You may experience some mild period type pains and tightening’s after it has been inserted.

You will be re-examined after 6 hours to check changes to your cervix and if it has dilated (opened) enough to have your waters broken. You can have additional tablets inserted (maximum of 3 in 24 hours) and you will be re-examined 6 hours after each tablet is given. If your cervix has not responded to the prostaglandin tablets then alternative methods will be offered and discussed with you.  

If your cervix is open and has started to thin out then it is likely we will recommended that your waters are broken artificially. This procedure is performed on Labour Ward. There can sometimes be delay in transferring you to Labour Ward to have your waters broken; this is dependent on room and midwife availability which could be anything from a few hours to over 24 hours but will be reviewed regularly.

The procedure is performed by a midwife or doctor who will insert a small, sterile plastic hook into the vagina to make a small hole in the bag of waters around your baby. After your waters have broken you will continue to leak amniotic fluid from your vagina until your baby is born, this is completely normal. Sometimes after you have had your waters broken you may experience irregular contractions however it’s likely that you will need oxytocin to get into labour (see below).

Oxytocin is the hormone that causes the womb to contract. It is given in a very small diluted dose directly into your veins via a cannula that will be inserted into your hand or arm. The midwife will monitor you and your baby throughout this process, including electronic fetal monitoring (CTG) of your baby’s heartbeat and assessing if you’re having any contractions. The midwife will adjust the amount of oxytocin you are given until you have 4 strong regular contractions every 10 minutes

If you’re aiming to have a vaginal birth after a previous caesarean birth and your labour needs to be induced, you will be offered a Foley catheter or Dilapan. These are mechanical ways of inducing labour.

At Warwick Hospital you may be eligible to go back home in the initial stages of your induction if yourself and your baby do not need to be monitored. This is using the non-hormonal methods of induction (Foley catheter or Dilapan). Ask your midwife or obstetrician if you are suitable for outpatient induction of labour.