What is an induction and when is it necessary?

Posted on June 7th, 2018

There are many reasons why a birth may have to be induced. Here’s what to expect. By Julia Boltt

What is an induction and why is it necessary?

Induction is when your labour is started artificially, using mechanical means, such as rupturing your membranes, or with medication. There are several reasons to induce labour, but the most important criteria is that the risks of prolonging your pregnancy outweigh the risks of delivering your baby.

About 10% of pregnant women will go beyond their due date, says specialist gynaecologist and obstetrician Dr Trudy Smith. The cut-off for pregnancy is considered to be 10 days past your due date, as placental function begins to decline at this point. “Once this happens, the risk of interuterine death is much higher,” she says. However, induction may also be considered if there’s a medical concern that is affecting you or your baby’s life – regardless of whether you’re past your due date.

ALSO SEE: 11 ways to induce labour naturally

How does it work?

To assess whether you’re a candidate for an induction, your midwife or gynae will use the Bishop score to rate the readiness of your cervix for the process. “The Bishop score helps us assess the readiness of the cervix through a number of criteria like the station of the head, dilation, how thin the cervix is and consistency of the cervix,” explains registered midwife Xoli Makabane.

A low score means that medication is necessary to ripen the cervix, while a high score means that the membranes can be ruptured and Syntocinon (oxytocin that stimulates contractions) administered.“An induction with a score of less than eight [out of a possible 13] is far more likely to end up with a C-section,” says Xoli.

ALSO SEE: 11 reasons why your gynae might insist that you have a C-section

If your cervix isn’t dilated or thin enough yet, your healthcare provider will ripen the cervix using medications. Sometimes this is enough to get the contractions started. If this doesn’t initiate labour, you may be given a drip delivering oxytocin, provided that the cervix is ripe. Your midwife may also rupture your membranes or use a catheter bulb to exert pressure on the cervix. Xoli says that this can take some time. “It’s important to be patient and wait between interventions to give them time to work before adding another medication or procedure,” she advises.

Will I be induced?

The most common reason for an induction is being overdue, says Dr Smith. Other reasons for an induction are if the baby has stopped growing, your membranes have ruptured but labour hasn’t started, or you are suffering from health complications like diabetes, cardiac disease or high blood pressure.

Placental concerns like placental insufficiency, growth restriction, oligohydramnios (deficiency of amniotic fluid) or abruptio placentae (premature separation of the placenta from the uterus) are also reasons for an induction, as are a multiple pregnancy, if you have experienced a previous abruptio, previous stillbirth, chorioamnionitis (amniotic fluid infection), foetal compromise (Rhesus disease) or, tragically, foetal demise, explains Dr Jana Rossouw, a specialist gynaecologist and obstetrician.

ALSO SEE: 3 placenta problems explained

Why an induction?

“A C-section is a surgical procedure that can have complications. Birthing is a natural process that is always preferred. A C-section was designed to save lives, not to be a primary method of birthing,” says Xoli. If you’re a good candidate for induction, the risks of a surgical delivery outweigh the risks of an induction of labour, explains Dr Rossouw. However, she adds, “it is absolutely imperative that induction of labour is only performed in hospital under direct supervision of a doctor, with nursing personnel, foetal monitoring, uterine contraction monitoring and theatre facilities for a C-section”.

Induction is not for everyone

Not every pregnant woman is a candidate for induction. If you are suffering from placenta praevia (your placenta is near to, or covering, your cervix), vasa praevia (your baby’s blood vessels run too close to your cervix), severe placental insufficiency, uncontrolled pre-eclampsia, have had two previous C-sections, suffer from severe cardiac or lung disease, have active genital herpes, severe obstructive genital warts or an abnormal pelvis, you’ll be ruled out as a candidate.

Other reasons to rule out an induction include a baby who has an abnormal lie, for example, a breech baby, in some instances of multiple pregnancies, or where the baby is large for gestational age (foetal macrosomia), says Xoli. Large for gestational age would be a baby weighing more than 4kg in a diabetic mom, or more than 4.5kg in a non-diabetic mom at the time of birth.