Induction of Labour
When the birthing process is started with medical treatment, this is called “induction of labour”. Induction of labour is usually undertaken if the risks of continuing the pregnancy are greater than the risks of induction to deliver the baby.
Some indications for induction of labour include:
- The pregnancy is seven or more days past the due date.
- The mother has a health condition such as high blood pressure or diabetes.
- The bag of waters (amniotic membranes) has ruptured but labour has not started.
- The membranes surrounding the baby are infected (chorioamnionitis) or the risk of infection is high.
- The placenta (which supplies oxygen and nutrients to the baby) is not working properly.
- The baby’s growth is slowing.
- The baby has a health condition and needs medical treatment.
- The woman lives far from medical services.
- Psychosocial reasons.
The woman’s experience during induced labour is usually similar to natural labour.
Before induction, the doctor performs a pelvic examination to find out whether the cervix has opened (dilated) and by how much. The state of the cervix helps to determine which induction method, or combination of methods, is best for the woman.
All induction methods aim to stimulate the onset of labour and contractions of the uterus.
The doctor cannot predict the time of onset of labour following treatment. It may take longer or shorter than expected.
Sometimes, the chosen induction method does not work, and the doctor may try again using another method. The doctor may reassess the need for induction or may consider a caesarean section to deliver the baby.
- Prostaglandin: This is a natural hormone that softens the cervix. The doctor or midwife performs a vaginal examination and places the prostaglandin around the cervix.
- Stripping of membranes: The doctor uses a gloved and lubricated finger to gently separate the amniotic membrane from the cervix.
- Artificial Rupture of Membranes (amniotomy): The doctor uses a slender instrument (amnihook) or small hook on a gloved finger to break the amniotic membrane.
- Oxytocin: During labour, the hormone oxytocin is secreted naturally from the pituitary gland in the brain. Oxytocin causes normal uterine contractions. In hospital, synthetic oxytocin can be administered through an intravenous drip inserted into the woman’s hand or arm. The dose is slowly increased until the uterus contracts efficiently.
- Balloon Catheter: The doctor inserts a thin catheter into the cervix. Once in place, the little balloon at the end is inflated with water. The constant pressure exerted against the cervix may help to dilate and soften.