THE STAGES OF LABOUR AND ITS COMPLICATIONS

From the moment you become pregnant, everything is leading up to the delivery of your baby. This, of course, can't happen without labour - unless for some reason you need to have your baby delivered by caesarean section before you go into labour.

Fortunately, the days when labour was inevitably painful and scary are long gone. New advances in pain relief mean that women have much more say over the kind of labour they want. Today, midwives and doctors are much more aware of the wishes of the mother, and will do everything they can to give you the labour that you want.

For most women, labour is a positive, uncomplicated and rewarding experience. About 17 in 20 women having their first baby will have a normal delivery - this rate rises to about 19 in 20 if you have had a normal delivery before.

But it is worth being aware that complications of labour do happen. They can, for the most part, be sorted out, but this may involve medical intervention that you hadn't expected. While staff looking after you will do everything they can to accommodate your wishes in labour, the safety of you and your baby has to come first. Knowing this, and being prepared for every eventuality, can go a long way towards stopping you from being disappointed.

The stages of labour

Labour is divided into three stages.

In the first stage, your uterus (or womb) starts to contract regularly, pushing your baby towards the vaginal entrance. At the same time, your cervix (the neck of your womb) begins to open up until it is fully dilated - enough to let your baby's head through. Your waters will usually break at some point in the first stage of labour.

The second stage of labour lasts from the time your cervix is fully dilated until your baby has been completed delivered.

The third stage of labour lasts from the time your baby is delivered to the time your placenta has been delivered. After your baby is born, your uterus still needs to push out the placenta or afterbirth. The placenta is both smaller and much softer than your baby(!), so this stage is usually much simpler than the second stage.

Terms used in labour

Perineum - the area outside your vagina, stretching back to your bottom
Dilation - how far open your cervix is. Before labour, your cervix is "zero cm dilated". When your cervix is 10cm dilated it is known as "full dilatation". At this stage you may be allowed to start pushing your baby out
Episiotomy - a cut in your perineum, going back at an angle from the back wall of your vagina
Forceps - a metal instrument placed round your baby's head to pull him out in the second stage. You will need an epidural or local anaesthetic for this
Ventouse - a suction cup attached to your baby's head to pull him out in the second stage - also needing an anaesthetic
Caesarean section - an operation to open up your uterus and bring your baby out. These days, this operation involves a horizontal cut just below your pubic hairline. It can be done under general or epidural anaesthetic.

Delays in labour

There are three main causes of delay in the first and second stages of labour:

Inadequate or ineffective contractions of your uterus

If your uterus does not contract often enough, or is "floppy", its contractions may not do their job properly. This can either stop labour from getting going , or slow down the dilation of your cervix. Breaking your membranes or waters (the membranes form the fluid-filled sac your baby floats in) will often help the contractions to get going effectively. This involved a vaginal examination, and can be uncomfortable but not painful.

If breaking your waters doesn't help your contractions, you may need to have a drug called Syntocinon. This is given through one of your veins with a drip. It stimulates your uterus and usually helps your cervix to dilate up normally. If you have a syntocinon drip, you will need to be attached to a machine so your baby can be monitored all the time.

If there are further problems, you may need to have a caesarean section. When - and whether - this happens will depend on several things. The most important are whether the baby is showing signs of being distressed, and what sort of shape you are in.

Once your cervix is fully dilated, you have reached the second stage of labour, in which your baby's head travels down through your vagina. How long you can safely push naturally depends on whether the baby's head is moving down, whether your baby is showing signs of distress and how much energy you have. At this stage forceps can usually be safely used to pull your baby out.

Abnormal size or position of your baby

Sometimes the first or second stage of your labour may be delayed because your baby's head is too large or in the wrong position. This is called cephalo-pelvic disproportion. Unless your baby is a real giant (more than about 9lb), his size is unlikely to have much effect on the length of your labour.

Your baby's head is not a perfect sphere, and it is much wider in some directions than others. When your baby's head is bent forward, with his chin on his chest, it is easiest to get his head out. As long as your baby is not lying with his back towards yours, then his head will usually turn during labour so that the narrowest part can pass safely through your pelvis.

If your baby is lying with his back towards yours, his position is described as being posterior or "occipito-posterior". This position stops his head from bending forwards normally. Because the wide part of his head is trying to get through your relatively narrow pelvis, labour can be delayed. Even if your baby has been lying in this position until labour starts, his whole body will often turn round during labour so that he comes out in a normal position. If his head does not turn round, getting him out will be much harder work, and you are quite likely to need a forceps delivery or even a caesarean section.

Occasionally, your baby may be bottom, rather than head, down. This is called a breech presentation. Breech babies can sometimes be turned round before you go into labour - do discuss this with your obstetrician. Breech babies can be delivered vaginally, but there is a higher chance of problems. Your midwife or doctor will discuss with you whether you want to try to have a normal labour, or a caesarean section if turning is unsuccessful.

Problems with the size or shape of your pelvis

Your baby's passage is determined not just by the size but by the shape of your pelvis - so don't worry if you've never had "child bearing hips"! Your height, and your shoe size, can give some guide to the size of your pelvis, but they aren't completely reliable. Having had a normal vaginal delivery in the past increases your chances of having a normal delivery next time round.

If you have had problems with your pelvis in the past, or if your baby's head does not engage in your pelvis before your first labour, you may be advised to have an x-ray to check that your pelvis is big enough for the baby to get through. However, this is rarely necessary, or even helpful.

The third stage of labour

In the third stage of labour the placenta usually comes away from the wall of your uterus in one piece. It can then be delivered quickly and safely. Giving an injection of Syntocinon (or syntocinon and ergometrine) usually helps this to happen. Occasionally the placenta fails to come away naturally, and has to be removed under epidural or general anaesthetic.

Foetal distress

Foetal distress suggests your baby is in trouble - usually from lack of oxygen. When your uterus contracts, it cuts off the oxygen supply to your placenta. If your placenta does not have enough in reserve, your baby may run into problems. Foetal distress can show up as:
- meconium (a green slimy liquid) in your waters
- changes in your baby's heart rate
- excessive movements of your baby.

If your baby shows signs of being distressed, you will need to be more closely monitored. You may also need help to speed up the delivery of your baby. What is needed depends on how severely your baby is distressed. If you are already in the second stage of labour, you may need an episiotomy or forceps delivery to speed up your baby's birth. If you are still in the first stage, you may need to have a caesaerean section.

Bleeding after delivery

If your uterus is empty (of both baby and placenta) and your cervix is not damaged, your uterus will almost always contract down to prevent any bleeding. Giving you Syntocinon or ergometrine as your baby is born helps it to contract more effectively, and if bleeding from the uterus does occur, a further injection usually does the trick. The risks are much higher if some or all your placenta are not delivered quickly after the end of your second stage.

Episiotomies or tears to your perineal area can bleed profusely, but this can usually be treated quickly and effectively with pressure and stitching to the affected area. Occasionally the bleeding may come from your cervix, which can be torn by a big baby or a very quick delivery. This too can usually be stitched under local anaesthetic.