What is induction of labour?
During pregnancy your baby is surrounded by a fluid filled membrane (sac), which offers protection whilst he or she is developing in the uterus (womb). The fluid inside is called amniotic fluid.
In preparation for labour the cervix softens and shortens, this is sometimes referred to as ‘ripening of the cervix’.
Before or during labour the membranes rupture (break) releasing the fluid. This is often referred to as ‘your waters breaking’.
During labour the cervix dilates (widens) and the uterus contracts to push your baby out. In most pregnancies labour starts naturally between 37 and 42 weeks, leading to the birth of the baby. Induction of labour is a process designed to start labour artificially.
When is induction recommended?
When it is felt that your or your baby’s health is likely to benefit, the doctor may offer and recommend induction of labour. On average about 1 in 5 labours are induced.
There are a number of reasons why induction may be offered and recommended, e.g. if you have diabetes or pre-eclampsia (high blood pressure in pregnancy that is affecting you or your baby’s health).
If you are healthy and have a trouble free pregnancy, induction of labour may be offered if your pregnancy is more than 41 weeks, or if your waters break before labour starts.
Even if you have had a healthy trouble free pregnancy, you should be offered induction of labour after 41 weeks because from this stage the risk of your baby developing health problems increases.
An ultrasound scan in early pregnancy (before 20 weeks) can help to determine your baby’s due date more accurately. This reduces your chances of unnecessary induction.
Using Prostaglandin Gel
Prostaglandins are medications that help to induce labour by encouraging the cervix to soften and shorten (ripen). They allow the cervix to open and contractions to start.
This is done in the Birthing Suite. Before giving prostaglandins your midwife will check the pattern of the baby’s heartbeat with a monitor or ‘CTG’. After being given prostaglandins you should lie down for at least 30 minutes for the monitoring. Once it is established that everything is fine, the CTG will be discontinued and you will be admitted to the maternity ward.
You will be asked to come in at 6 am. Your doctor will perform an internal examination and insert the prostaglandin gel if your cervix is not ‘ripened’ or open enough to allow breaking of water. You have to remain on your back for 2 hours after insertion. You will be review again at 12 midday if labour has not started in the meantime.
Prostaglandins sometimes cause vaginal soreness and uncomfortable contractions, backache or period like pains. Very occasionally prostaglandins may cause the uterus to contract too much which may affect the pattern of the baby’s heartbeat. If this happens you may be given a medication to relax the uterus and any prostaglandin gel remaining in your vagina will be washed out.
Breaking of ‘waters’
(artificial rupture of membranes)
If at the first vaginal examination your cervix is found to be favourable (ripened/open enough) and the CTG monitoring suggest that everything is fine with the baby, the doctor will break your waters with a small plastic instrument (called an Amnihook) and allow the amniotic fluid to be released. Breaking of ‘waters’ doesn’t usually hurt and will cause no harm to your baby; however, the vaginal examination itself may be uncomfortable.
Oxytocin is usually required after breaking of ‘waters’ to encourage contractions. It is given through a drip and enters the bloodstream through a tiny tube into the vein in the arm. Once contractions have begun, the rate of the drip can be adjusted so that your contractions occur regularly until your baby is born. Your baby’s heartbeat should be monitored continuously with the CTG monitor while you are on the oxytocin, to make sure the baby is coping with the contractions.
If 2 doses of Prostaglandin gel have not ripened your cervix, and the doctor has not been able to break your ‘waters’, an oxytocin drip will be started to encourage contractions and hopefully start opening your cervix.
Sometimes, in spite of all the above, you are still not in labour, Caesarean section may have to be considered. Your doctor will discuss this fully with you before any decisions are reached.
Please ask the doctor or a midwife any questions or raise any concerns you may have.