Induction of Labour
While the majority of pregnant women go into labour naturally, some women need a little bit of help. Perhaps they are over their due date or have a medical issue that warrants giving birth soon. Whatever the reason, if you are going to be induced, you will likely have questions. Will it be painful? How is it different from regular labour? What will be used to induce labour? Put your mind at ease and get a better idea of the process by reading on.
Induction of labour is carried out when it is felt that your baby is better off out of you than inside. This means that something is making its residence in your womb risky - be it for you or the baby.
The most common reason for inducing labour is due to going over dates. Other reasons include diseases of pregnancy (eg. preeclampsia), poor growth in the baby, or unexplained bleeding at term. The aim when inducing labour is to make it as much like a normal labour as possible. By doing this, the chances of a normal delivery are increased, and it it needn't be more painful.
How are Contractions Started?
The hormone your body makes during labour is called oxytocin. It is made in a small area of the brain and released into the blood stream via the pituitary gland. How your body actually starts labour is still not known, in spite of many years of research. We know many of the hormonal changes that happen, but the actual trigger remains elusive.
Oxytocin has been produced in the laboratory and the synthetic drug is used to start the uterus contracting. Unfortunately, it is not well absorbed in the stomach and needs to be given by a drip. This route of administration also means that the concentration of oxytocin can be increased or decreased should your contractions be too intense or not strong enough.
Breaking the Waters
If we just start oxytocin going, you will start contracting, but the contractions are not as efficient as when your waters have gone. Because of this, it is usual not to start oxytocin until the membranes around your babe have been broken. This sounds painful, but in fact is little more uncomfortable than a normal vaginal examination (which is uncomfortable enough!).
During an examination a small instrument called an Amnihook is used to nick the membranes in front of the baby's head - it looks very much like a crochet hook. This is also called an ARM or artificial rupture of the membranes.
Once the membranes have gone, it is usual to start oxytocin to get the contractions started. Sometimes, particularly if you've had several babies before, your obstetrician may suggest you get up and about for a couple of hours to see if you start contracting on your own. If its your first, there's little to be gained by waiting and oxytocin is started.
My Cervix is Still Closed or 'Unfavourable'
For the main part of pregnancy, your cervix is thick, long and closed, like a cork, helping keep the baby inside. As you approach term, the cervix progressively softens, shortens (effaces) and starts to dilate. This is what all those prelabour contractions are about. Also, your cervix releases some hormones locally, called prostaglandins. These are responsible for the changes described above.
If you go to be induced and your cervix is still thick and/or closed, you will most likely have a prostaglandin (Prostin) gel or pessary inserted. This brings about these changes, making it possible to rupture the membranes. The gel typically takes about 6 hours to work. Some hospitals put the gels in at night, then re-assess you in the morning. Some start in the morning and try and get you started at tea time.
Using the prostaglandin gel makes your labour much more natural if the cervix is thick. It certainly reduces the number of caesarean sections, which used to be associated with inductions of labour in women with an unfavourable cervix. Sometimes, it is necessary to use more than one gel treatment before ARM is possible. Many women start contracting and go into labour a few hours after having the gel.
Is it More Painful Being Induced?
This is the big question for most women. Unfortunately, there's no good evidence from studies to suggest one way or another. You will hear (particularly on the internet) about how awful inductions are from some women, but others report it being not much different to when they went into labour on their own.
Some places (especially in the US) don't use prostaglandin gels, as it has only recently been licensed, although their use is increasing. This means that contractions are started with an unfavourable cervix, often with the membranes still intact. So, not only is it unnatural for the contractions to start with the cervix still thick, the contractions are less effective.
When oxytocin is started, contractions do come on more suddenly than they might do if you went into labour spontaneously, so you've not been prepared by the early/prelabour contractions. The contractions aren't necessarily more painful per se, just that they started more quickly. It is usual to start the drip slowly and increase it gradually as your contractions start. Aim for three to four contractions in 10 minutes, which is about the same as established natural labour. The drip can be turned down as well as up.
For more information on your labor and delivery check out our pregnancy videos.