INDUCTION OF LABOUR
What is Induction of Labour ?
This is the name given to the starting of labour by artificial means. It is done because the health of either you or your baby is at risk if the pregnancy continues. Labour is induced in about 1 out of 7 pregnancies. Why is Induction of Labour performed ?
There are many different reasons for inducing labour. One of the main reasons is a pregnancy continuing beyond 42 weeks. In most prolonged pregnancies, the baby is not at any increased risk. However, after 42 weeks, there seem to be few advantages to either you or your baby in continuing the pregnancy, and most doctors will offer to induce your labour. Before inducing your labour for this reason, it is very important to be certain that your dates are correct. An ultrasound (like a radar picture) scan in early pregnancy is accurate to about one week and is a useful way of checking your dates. Various disorders, such as diabetes, high blood pressure (including pre-eclampsia, and kidney disease) can put either mother or baby at risk if the pregnancy continues. Bleeding in late pregnancy is another reason to induce labour. Some babies do not grow well whilst inside the womb. Leaving the baby to develop so slowly could result in the baby dying (stillbirth). If such poor growth is detected, labour is often induced before 40 weeks. A rare problem affecting a baby is called Rhesus disease. This occurs when a woman with a Rhesus negative blood group is bearing a baby who is Rhesus positive. Under these conditions, the mother can develop proteins called antibodies. These can flow back via the afterbirth into the baby during later pregnancy, damaging its blood cells and causing severe anaemia and jaundice: delivering the baby early lessens the risk of damage to the baby. Sometimes your membranes (waters) break, causing the fluid around the baby to drain, and yet labour does not start. The decision when and whether to induce your labour then depends on whether there is any sign of an infection getting into the womb, as well as how far on your pregnancy is. Sometimes the decision is difficult. The risk to you or your baby of carrying on the pregnancy have to be balanced against the problems of induction of labour and the prematurity which might affect your baby. The decision will depend on how strong the reason for induction is, how close to 40 weeks pregnancy you are, and whether on examining you, conditions are found to be favourable for induction. Because of all the different factors involved, it is not possible to set firm guidelines no two cases are the same. Your doctor and midwife will discuss all the issues involved with you, so that the approach can be an agreed one. What Happens during Induction of Labour
There are different way of inducing labour. First, you will be carefully examined by your doctor. The best way of inducing labour depends on whether your baby's head has already entered your pelvis. Your cervix (neck of the womb) changes before labour starts, and a vaginal examination is needed to find out whether these changes have occurred. If your baby's head has entered your pelvis and your cervix has changed in order to prepare for labour, then conditions are said to be "favourable for induction of labour". Your doctor will then arrange a date for you to attend the labour ward for your labour to be induced. If conditions are "favourable", the membranes around your baby will be broken. Your doctor will carefully examine your cervix and then break the membranes in front of your baby with a small hook. The fluid (or waters) around your baby will then drain until your baby is born. Sometimes breaking the membranes is enough to start your labour. Often, however, you will need to have a hormone (called oxytocin) given through a drip into a vein in your arm. This will get your womb to contract properly. The hormone used is the same as the natural hormone which causes contractions in the natural labour of all pregnant women. The amount of hormone you are given will be increased until your contractions are strong enough and regular enough to cause your cervix (neck of the womb) to open. If conditions are "not favourable", the neck of the womb must be encouraged to change before the waters can be broken. Substances called prostaglandins are usually given before the membranes are broken, to relax the cervix. These are usually given as a gel or tablet around the cervix at the time of your examination. They can also be given as tablets that you take by mouth. You will be examined every few hours to see if more prostaglandins are needed, or if your membranes should be broken. Possible Complications during Induction of Labour
Induced labours are often longer than natural labours. Sometimes it is not possible to induce a proper labour, and your baby then has to be delivered by Caesarean section. If too much hormone causes your womb to over-contract, your baby may become distressed. This is because its oxygen supply is reduced. Less common complications include the cord coming down in front of the baby's head at the time of breaking the membranes. Breaking the membranes can also lead to infections inside the womb. The nature of these complications mean that you are about three times more likely to eventually need a Caesarean section or a forceps delivery if your labour is induced, than with a natural labour. After Induction of Labour
Because you have had one pregnancy induced, it does not necessarily mean that all future pregnancies will also need to be induced. |
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