What IS induction?



Induction of labour describes a process of bringing on uterine contractions to start the process of giving birth sooner. It is often suggested if you are over 40 weeks pregnant, or are deemed high risk due to gestational diabetes, premature rupture of membranes or concerns over baby being “too small” or “too large”.


It’s important to make sure you are properly informed of both the perceived risks of continuing your pregnancy AND the risks of induced labour. Asking for the medical research which backs up the recommendation is advisable.

So HOW is labour induced?


There are many stages to induction, and not all may be necessary if labour is triggered.


Membrane sweep

A sweep, sometimes called a stretch and sweep, or “sweeping the membranes” involves a midwife inserting a finger in to the vagina and past the cervix (the opening of the uterus) and using a sweeping motion to separate the membrane that surrounds baby from the lower part of your uterus. This can only be done if you are already 1cm dilated or more. If your cervix is not “favourable” the procedure cannot be done.


Research is mixed as to whether a sweep actually works to induce labour. There is evidence to show that if done at 41 weeks it may reduce your chances of going over 42 weeks. Evidence also shows it may shorten your pregnancy by an average of 4 days. However, as your cervix needs to already be favourable and dilated, there’s no way of knowing if you’d naturally go in to labour on your own without the sweep and when that could happen.


Are they risk free? The simple answer is no. A sweep may introduce infection, and it may cause bleeding. Some people find it painful and uncomfortable, or even triggering. There is a 1 in 10 chance of your membranes being accidentally ruptured. If this happens, and labour doesn’t start, it can lead to further induction procedures. It can also cause irregular contractions and a longer labour.


Sweeps are NOT compulsory so consider carefully whether you consent or not. As with everything in labour, it’s YOUR choice!

Prostin pessary

The prostaglandin pessary is a synthetic version of prostaglandins and is placed inside or as close to the cervix as possible. It can be a tablet, pessary or gel.


This helps to soften and dilate the cervix and stimulate surges which hopefully will continue and lead to labour. If baby was likely coming soon anyway then this may be all that is needed to get things going.


Usually there is a gradual build up of surges but as this uses artificial hormones, the sensations can be more intense. Sometimes it can overstimulate the uterus which would require the pessary is taken out.

Balloon induction

A soft catheter with inflatable balloons is inserted in to the vagina and through the cervix and inflated. This helps dilate the cervix and the pressure stimulates the production of prostaglandins which trigger labour and ripen the cervix. As this method doesn’t use artificial hormones it shouldn’t affect your natural production of birth hormones and may be sufficient to trigger labour.


As with any vaginal procedure in labour, there is a risk of infection, which would mean a longer stay in hospital and antibiotics for you and baby. It can also be uncomfortable.


Artificial rupture of membranes

This is when the sack that contains the baby and waters is broken with a small hook. This forces the baby’s head to press down on the cervix to stimulate surges and dilate the cervix. With the waters intact, the surges are cushioned and less intense. When the waters are released, surges are far more intense due to the uterus pressing against the baby during each surge.


There is an increased risk of infection without the barrier there to protect baby so be mindful of having vaginal exams which can introduce bacteria to the area.

Syntocinon drip

This is synthetic oxytocin which is administered via an IV. Following breaking your waters, Syntocinon is increased via a catheter in the hand until surges are coming every 3-4 mins and lasting around 1 min.


It is very effective at stimulating surges but the surges are different to those of spontaneous labour. During a physiological labour, your body produces oxytocin and endorphins gradually, increasing the intensity of your surges and the amount of pain relieving hormone with it. With induced labour using artificial oxytocin, labour ramps up quickly but without the benefit of your pain relieving endorphins.


Syntocinon is known to have an affect on baby’s heart rate in most cases so it is advised to have heart rate monitored via a CTG. The drip will be increased until it has an affect on the heart rate and then decrease a little again.


Syntocinon is also associated with postnatal depression and parents feeling less able to bond with baby. Other risks include increased rates of episiotomy, instrumental delivery, hypnotension, tachycardia, uterine rupture and clotting.


It’s important if you’re considering consenting to induction to weigh the risks of waiting for labour to start naturally vs the risks of induction itself. Reading up on the latest research and ensuring you’re clued up on the facts. Hannah Dahlen et al conducted a research study of over 47,000 births and followed the babies over 16 years to see the effects of induction of labour over the short and long term. The findings are EYE OPENING.


So what did this study find?


  • higher rates of instrumental births, c-section, episiotomies, tears and postpartum haemorrhage amongst those who were induced vs those who went in to spontaneous labour

  • short term, they found higher rates of admission to NICU, asphyxia, birth trauma, resuscitation, and respiratory disorders in babies who were induced

  • long term, the higher rates of hospital admission for ear, nose and throat infections in those babies who were induced

  • the study did not find any benefits of IOL for neonates, at any term gestation of labour onset, when induced for non-medical reasons


Whilst induction of labour may be advised for certain medical reasons, it’s vital that parents fully understand BOTH the risks and benefits, in order to make an informed decision. Induction of labour for non-medical reasons needs to be re-evaluated. Inductions are not risk free, and the risks may outweigh the potential benefits.


You can read the full study here: https://bmjopen.bmj.com/content/11/6/e047040

55 views0 comments

Recent Posts

See All