Induction of labour is the initiation of labour by artificial means when the pregnancy is mature enough to deliver a viable foetus (baby).
Induction become necessary when there is obvious risk either to the baby or the mother and keeping the pregnancy is no longer accepted. Then, immediate intervention by putting an end to the pregnancy becomes the only reasonable option.
This can be achieved either by surgical intervention, that is to perform operation to deliver the baby (Cesarean Section) or induce the pregnant woman to deliver normally if she is qualified for induction of labour. The goal of induction of labour is to achieve vaginal delivery.
Normal onset of labour is a complex process that starts spontaneously with low back-ache, lower abdominal pain, passage of mucus blood-stained discharge called “show,” and progress to regular repetitive uterine contraction of significant frequency, intensity and duration to cause progressive cervical dilation and effacement, leading to the descent of the presenting part (of the baby in the birth canal). Hence, the foetus and the placenta are expelled through the birth canal.
Spontaneous onset of labour may never occur in some pregnant women, even after they have long passed their due date. Normally, the due date from the first day of the last menstruation is 40 weeks. For such women, artificial intervention to initiate the onset of labour may be necessary to avoid complications of prolonged pregnancy, which may include death of the baby in the womb.
Other reasons for induction of labour include complications associated with pregnancy, which may include high blood pressure in pregnancy (pregnancy-induced hypertension), hypertension in pregnancy with leakage of protein in the urine (pre-eclampsia), poor foetal growth (intra-uterine growth restriction), death of the baby in the womb, recurrent bleeding before onset of labour (ante-partum haemorrhage), excessive water in the bag of the baby (polyhydramous), or diabetes in pregnancy.
The most common reason for induction of labour is prolonged pregnancy because there is evidence that pregnancy that extends beyond 42 weeks is associated with high risk of uterine foetal death (death of the baby in the womb) or stillbirth. Also, the majority of babies cope poorly with labour and die during labour or shortly after delivery. So, induction of labour is usually recommended before 42 weeks of pregnancy, counting from the first day of the last menstrual flow.
To avoid some complications that may arise from induction of labour either to the baby or the mother, the patient must be carefully selected, method to be used must be critically reviewed with the patient at hand, vis-à-vis the past history of the patient; and labour must be monitored closely.
There are various methods of induction of labour that are readily available in our environment. They range from simple procedures like membrane sweeping or stripping (also called stretch and sweep in another environment). During examination, finger is put in the cervix to stimulate the membrane and separate from the presenting part of the baby. This maneuver releases prostaglandin, a substance that may help to initiate uterine contraction and labour. The use of intra-cervical Foleys catheter will also achieve the same goal.
Artificial rupture of membrane or “breaking of water” also stimulates uterine contraction and set labour in motion.
The use of Oxytocin (a drug that helps to stimulate contractions of the uterus and smooth muscle tissue) is very common for induction of labour, and even less educated women know about it. Most women describe it as ‘hot drip’ because the contraction achieved is usually very strong and very painful.
Prostaglandin vaginal pessary is less available because it is expensive and must be kept in the refrigerator to be effective; otherwise, it will melt out in normal room temperature. Low dose misoprostol is commonly used in our environment because it is effective and stable at room temperature.
As useful as induction of labour is, especially when delivery becomes the only option for the safety of the baby or the mother or both, artificial initiation of labour is contraindicated in some group of pregnant women. For example, women who have had at least two deliveries through Cesarean Section, previous uterine rupture, pregnant women with Vesico-Vaginal Fistula from previous pregnancy or women with previous extensive uterine fibroid operation may also not be good candidates for induction of labour.
Complications that may arise from induction of labour may include abnormal foetal heartbeat, foetal distress, and weakness of the baby and even death of the baby during labour or shortly after delivery. The woman in labour may become exhausted, or suffer ruptured womb during labour or even death.
When inducing labour, there must be a doctor that can perform surgery in case of any complications that may arise during the process of induction, either as a result of the baby in distress or if there are challenges with the woman in labour, such as maternal distress, sign of uterine rupture, etc.