How is labour induced?
Around 30% of women are recommended an induction of labour for varying reasons.
Your midwife or obstetrician will have a full discussion with you in the antenatal period routinely at your 36 or 40 week appointment regarding induction of labour and the benefits and risks of this, enabling you to make a fully informed decision. Methods used to induce labour vary depending on a range of factors. Your doctor and midwife will discuss the different methods with you and advise a method based on your personal circumstance.
When you come into the maternity unit for your induction, a midwife will undertake a full assessment of you and your baby and this will include electronic fetal monitoring (CTG) of your baby’s heartbeat and to see if you are having any contractions. Then the midwife or doctor will assess your cervix by undertaking a vaginal examination. Following this examination options for induction will be discussed with you.
Some women may need only one of the steps below and others will need all three to get them to established labour (four centimetres dilated with strong, regular contractions):
Step 1
Prostaglandin
Many women find that their cervix is not quite ‘ready’ for labour yet, and in this case your midwife will insert a gel or pessary containing a hormone known as prostaglandin during vaginal examination. The gel works over six hours, and you will be asked to stay in the maternity unit for this time. The pessary is released slowly over twenty four hours, and if you and your baby are responding well you may be able to go home during this time. Some women find that the gel or pessary is enough to start contractions and labour. Other women may not experience any changes. After the medication has had time to work, a midwife will assess the cervix again and see if it is possible to break the waters. Some women may be offered further doses of prostaglandins.Step 1
Balloon catheter
Some Trusts offer the balloon catheter as the very first step in the induction process. If the prostaglandin pessary does not work or is not suitable for your circumstance, you may be offered a balloon catheter. This is a small balloon which is inserted in the cervix, putting pressure on it, causing your body to release its own natural labour hormones that may cause mild cramps and dilatation of the cervix. The balloon catheter works over 12 – 24 hours to stretch and soften the cervix in preparation for labour.Step 2
Amniotomy
Some women (particularly those who have had a baby before) may be told that their cervix is thin and starting to open. In this case it will be recommended that your waters are broken artificially, this is called amniotomy. A midwife will insert a small sterile hook into the vagina to make a hole in the bag of waters that surrounds your baby. After the waters are broken, labour may start on its own. Amniotic fluid may continue to drain from the vagina for the duration of your labour.Step 3
Oxytocin drip
For those women whose contractions do not start after the waters are broken, a hormone called oxytocin will be recommended. Oxytocin is diluted and given in small amounts directly into a vein through a cannula inserted into your hand or arm. The oxytocin drip causes your womb to have contractions. The drip is usually given continuously until your baby is born. A midwife will be caring for you and monitoring you and your baby closely for the duration of labour.
Understanding induction of labour – a video developed by clinicians, women and a local hospital charity in North West London.