What is an Induction of labour?

What is an Induction of labour?

Induction of labour is the process of starting labour artificially, rather than waiting for the mother to go into labour spontaneously.  Approximately 20% of women in New Zealand have their labours induced.  The aim when inducing labour is to make the process as much like a normal labour as possible.

Why would I have my labour induced?

Induction of labour is carried out when it is felt that your baby would be better off out of you than inside.  This means that something that is making continuing the pregnancy risky - either for you or the baby.

There are many reasons why women may be advised to have their labour induced or started before the body has gone into labour spontaneously.

The most common reasons for induction are:

• Overdue or post dates - When a pregnancy continues after 40 weeks, there is a risk that the placenta will work less well and therefore not supply sufficient nutrients and oxygen to your baby, therefore putting your baby at risk.  Because it is not possible to accurately predict which placentas will not continue to function well, induction of labour is recommended between 41-42 weeks gestation. 
• Pre-eclampsia - when your blood pressure has risen, you have swelling on your ankles and feet and where there is protein in your urine.
• Reduced growth or reduced movements from your baby.
• Diabetes
• Spontaneous rupture of membranes (your waters break) prior to going into labour.

A stretch and sweep of the membranes

Before an induction of labour, your Midwife will offer a sweep of the membranes.  This is a procedure where the Midwife will perform a vaginal examination and the cervix is examined and 'swept', using a circular, sweeping movement to separate the membranes from the cervix.

Benefits

•  Increased possibility of labour starting naturally within 48 hours.
•  Possibility of not needing a formal induction of labour.

Risks

• The procedure may cause some discomfort but will not cause any harm to you or your baby.

Why is labour induced?  

There are several ways this may be achieved.

Artificial rupture of the membranes (ARM)

During pregnancy a fluid filled membrane sac surrounds and protects your baby while he or she is inside the womb.  In preparation for labour, the cervix (neck of the womb) softens and shortens.  This is called 'ripening of the cervix.'  and either before or during labour the bag of membranes break, releasing fluid.  This is known as 'your waters breaking.'

One way your labour may be induced is by artificially breaking your waters (ARM), this can only be done if your cervix is soft and has started to dilate (open).  If your labour does not start following an ARM, you may need to have an intravenous drip put into your arm and an artificial hormone called Syntocinon is started o make your womb contract.  

Breaking your waters should not be painful, it may be slightly uncomfortable.

Benefits

• Labour occurs.
• Labour may be shortened marginally.
• Information gained regarding the well being of your baby.  The water surrounding your baby should be clear in colour, if the water is not clear, your Midwife will monitor your baby more closely.

Risks

• Very rarely the baby's cord could come out (prolapse).  Midwives and Doctors are trained not to attempt an ARM if there is a risk this may occur, they are also trained to managed the emergency situation should it happen.
• During the vaginal examination by the Midwife, if your cervix is favourable, or has opened enough for your waters to be broken (if intact), a small instrument called an amnihook can be used to break your waters.  This is called 'artificial rupture of the membranes' or ARM.

This may be all that is needed to stimulate the uterus to contract and go into labour.  When your waters are broken, whether spontaneously or artificially, fluid will continue to drain out until your baby is born.

Prostin Gel

This is a drug intended to soften, shorten and open the neck of the womb (cervix).  It is put into the vagina next to the cervix at six hour intervals until you are in labour.

Once this process starts to happen, labour often follows naturally.  However, there is no guarantee this will happen and you may to have an ARM in addition to the prostin gel.

Benefits

• Labour process is started.

Risks

• Your baby's heartbeat will be monitored on the machine (CTG) before and after the insertion of the Prostin gel, so you will unable to walk around for the short time while you are being monitored.  Once your baby has been monitored, you will be able to get up and walk around but you will not be able to leave the hospital until your baby is born.  The Prostin gel is given six hourly.
• Prostin gel may cause vaginal irritation.
• It may cause 'period' type pains in your lower abdomen and backache.  During this stage, showers, warm baths, heat packs and massage may help.  If necessary, the Midwife can give you pain relief such as paracetemol.
• It may not work with the first dose and several doses may be necessary.

Syntocinon infusion (Oxytocin)
This hormone is similar to the one produced naturally by your body and is given to stimulate contractions.  It is given via an infusion pump into a vein in your arm, also called an intravenous drip.  This would only be given if your waters have broken either spontaneously (naturally) or artificially (ARM).

Benefits

• Labour may be shortened.

Risks

• Loss of mobility.  An intravenous drip will be inserted into your hand or arm and your baby's heart rate as well as your contractions will be monitored on the CTG.
• Your contractions are monitored on the CTG and the dose of syntocinon will be increased or decreased according to the number of contractions you have in a ten minute period.
• The need for pain relief may be increased.

Please speak to your Midwife if you have any questions regarding induction of labour.