Induction of labour is the process where contractions are initiated to simulate labour. Inductions are common, occurring in 20 – 25% of all pregnancies. Some of the most common reasons for induction of labour include:
- When your baby is overdue
- Medical conditions such as high blood pressure (pre-eclampsia) or diabetes
- Concern for baby’s health (when your baby’s growth is either suboptimal or excessive, decreased fetal movements)
- Elective induction (maternal choice)
How an induction is performed will depend on how favourable the cervix is at the time. This is assessed by an abdominal palpation, as well as an internal exam to assess where the baby’s head is in the pelvis, but also to determine whether the cervix is soft and/or dilated.
Modes of inductions include:
- Stretch and sweep. This involves an internal and the cervix is stretched and the membrane is swept from the cervix in order to stimulate the hormone (prostaglandin) release from the cervix. This will only be successful if the cervix has started to dilate.
- Vaginal gel or pessary containing a hormone called prostaglandin. This is usually given in the evening and aims to soften and ripen the cervix if the cervix has not started to dilate prior to induction of labour. Sometimes a second dose of the gel may be necessary.
- If the cervix has started to dilate prior to an induction then the waters are broken, a syntocinon (hormone) intravenous infusion is started. In some cases, vaginal gel, breaking of waters and hormone infusion is required.
One of the common misconceptions is that an induction of labour will hurt more than a spontaneous labour. The main difference with an induction is the early phase of labour is significantly shorter than a spontaneous labour and as such labour may come on more quickly.
The good news is that an induction will not change the way you deliver. In other words, if the induction ultimately ends up in a Caesarean section because the baby fails to fit through your pelvis or gets distressed in labour this was more than likely going to happen in a spontaneous labour. The whole aim of an induction is to simulate a normal labour.
Generally the most important aspect of whether an induction will succeed is where the baby’s head is in the pelvis. If the baby’s head is high and unengaged, the likelihood of an induction failing or ending up in a Caesarean section is significantly higher.