It’s generally known that waiting for labour to begin on its own is best for mother and baby.
Sometimes it’s necessary for labour to be started artificially (induction) if the risks of prolonging your pregnancy outweigh the risks of having your baby immediately.
Problems requiring an induction include pre-eclampsia, high blood pressure, fetal distress and maternal health problems (diabetes, kidney disease). In these situations, it helps to know what induction methods may be offered and the risks and benefits of each.
It’s important to bear in mind that all forms of induction can increase your risk of assisted birth or c-section. Once an induction has begun, in most cases, you're committed to delivering your baby in whatever way necessary.
There are several different induction methods, and each mother and baby will respond to them uniquely. For this reason, no two inductions are the same.
5 Different Medical Induction Methods
Here are 5 different induction methods:
#1: Membrane Sweep
If your cervix is slightly dilated or favourable, a stretch and sweep of the membranes may be offered as a drug free option to induce. Your care provider will insert their finger into your vagina and inside your cervix, sweeping or separating the membranes surrounding your baby from your cervix.
You may experience some cramping and bleeding afterwards. If the first stretch and sweep doesn’t work, you may be offered two or three more sweeps before moving onto other induction methods.
- Can feel uncomfortable or painful depending on the person performing the procedure and how difficult your cervix is to reach.
- Risk of bacteria being pushed up to the cervix even though sterile gloves are used.
- Failure to start effective contractions, leading to maternal exhaustion and further interventions.
#2: Artificial Rupture of Membranes
Artificial Rupture of Membranes (ARM) or breaking the waters is usually only used in conjunction with another method of induction (such as artificial oxytocin).
If your cervix is favourable (slightly dilated) a special hook inserted to create a hole in the amniotic sac. This causes the amniotic fluid to leak and production of prostaglandins increases, causing contractions to speed up.
The complications of ARM are:
- Insertion of a finger or implement to break the sac increases the risk of infection
- If the baby’s head is high or not engaged there is a risk of the umbilical cord being swept out before the baby’s head (cord prolapse). This is a medical emergency.
- Baby can move into a less favourable position for birth
- Rupture of a vasa praevia (blood vessels that insert into the placenta cover the cervix).
#3: Prostaglandin Gel
Prostaglandin is a hormone that stimulates contractions. It also acts to soften and dilate the cervix. Dinoprostone (Cervidil) and Misoprostol (Cytotec, more commonly used in the US) are two types of prostaglandins used for labor induction.
Your care provider will insert the gel into your vagina up near your cervix. It may take more than one dose in tablet or gel form to stimulate labour but the pessary form releases the hormone over 24 hours and should only require one dose.
Risks of prostaglandin use include:
- The synthetic hormone can cause excessively strong contractions that are painful and lead to pain relief and other interventions
- Hyperstimulation of the uterus which can result in fetal distress
- Hyperstimulation can cause uterine rupture, especially in women having a vaginal birth after c-section (VBAC).
#4: Synthetic Oxytocin
Known as Syntocinon or Pitocin, artificial oxytocin is commonly used for induction.
During an unmedicated labour, oxytocin is released by your brain to stimulate contractions. As labour progresses and contractions intensify, your brain releases painkillers called endorphins. As the levels of endorphins rise, so does the oxytocin levels – increasing the strength and length of contractions.
When labour is stimulated by artificial oxytocin it only acts on the muscles of the uterus. Synthetic oxytocin doesn’t cross the blood-brain barrier, meaning the brain cannot release natural painkillers in response to the rising oxytocin levels.
Synthetic oxytocin is given via an IV drip. Usually a low does is used to begin but the levels are increased until your uterus is contracting to a set amount/consistency per hour. Because your body is being ‘forced’ to create strong contractions very quickly and is unable to produce endorphins, the contractions may be extremely painful and intense.
Due to the risks of induction with artificial oxytocin, you will be required to be monitored, which often restricts your ability to move. This can lead to you requesting pain relief as well as fetal distress.
Risks of Sytocinon/Pitocin include:
- Hyperstimulation of the uterus, causing fetal distress or uterine rupture
- Low blood pressure (hypotension)
- Excessive bleeding following birth (postpartum haemorrhage)
- Assisted birth (episiotomy, forceps, ventouse)
- High doses over a long period can cause water to be retained and sodium concentrations to drop in your blood (water intoxication)
- Maternal nausea, vomiting or diarrhea.
#5: Balloon/Foley Catheter
Mechanical methods to prepare the cervix for labour are one of the oldest methods of induction. Since the advent of synthetic oxytocin, the use of mechanical methods of induction have lowered.
A balloon catheter (often called a Foley’s Catheter after the surgeon who designed the original) applies pressure on the cervix in the same manner as the baby’s head would. A small rubber tube is placed through the cervix and a balloon inside the tube is inflated with saline fluid. This balloon is sitting just inside the inner edge of the cervix.
Over time, the pressure of the inflating balloon encourages the cervix to dilate. Once the cervix has dilated to around 4cms the balloon will pass through the cervix and fall out. There is little risk of infection or pre-rupture of membranes using this method of induction.
Induction of labour is one of the most common procedures used in maternity care today. Many women who schedule elective inductions (for non-medical reasons) will go on to experience high levels of intervention for failure to progress – increasing their own and their babies’ risks of serious injury or complications. Once an induction has begun, the situation becomes high risk and requires ongoing management. An induction often means you are committed to doing whatever is necessary to get the baby out.
There are certainly times when the benefits of induction outweigh the risks, such as pre-eclampsia, fetal distress is present, or there’s an immediate concern with either the mother or baby’s health. If your care provider believes medical induction is necessary for the safety of you or your baby, they should discuss all the risks and benefits in relation to your situation. It’s important you’re able to make an informed choice based on what is safest for you and your baby.
It's definitely possible to have a positive induction experience. See our article, 8 Tips For A Positive Induction Of Labour.