What's the best position for my baby to be in?

Labour is nearly always shorter and easier if your baby is in a head-down position, with the back of his head slightly towards the front of your tummy. This is called an anterior position. Most babies get into this position by the end of a pregnancy.

In an anterior position, your baby fits snugly into the curve of your pelvis. During labour, your baby will curl his back over and tuck his chin into his chest. Your labour and birth should progress easily if your baby is in this position because:

• The top of your baby's head puts rounded, even pressure on the neck of your uterus (cervix) during contractions. This helps your cervix to widen and helps to produce the hormones you need for labour.

• At the pushing stage, your baby moves through your pelvis at an angle so that the smallest area of his head comes first. Try putting on a tight polo-neck top without tucking in your chin and you'll understand how this works!

• When your baby gets to the bottom of your pelvis, he turns his head slightly so that the widest part of his head is in the widest part of your pelvis. The back of his head can then slip underneath your pubic bone. As he is born, his face sweeps across the area between your vagina and back passage (the perineum).

What's a posterior position?

A posterior position is where your baby has his head down, but the back of his head is against your spine. By the time labour starts, about one baby in 10 is in this back-to-back or posterior position.

Most back-to-back babies are born vaginally, but this position can make labour more difficult for you, particularly if your baby's chin is pushed up rather than tucked in. As a result:

• You may have backache as your baby's skull is pushing against your spine.

• Your waters may break in early labour.

• Your labour may be long and slow.

• You may feel like pushing before your cervix is fully dilated.

When your baby gets to the bottom of your pelvis, he'll need to turn through almost 180 degrees to get into the best position to be born.

This can take quite a while, or your baby may decide he's not going to turn at all! In this case, he will be born with his face looking up at you as he emerges. He might need forceps or ventouse to help him out.

Why are some babies posterior?

Your baby may be posterior because of the type and shape of pelvis that you have. Some women have a pelvis which is narrow and oval (called an anthropoid pelvis) or wide and heart-shaped (called an android pelvis), rather than round-shaped.

If your pelvis is oval or heart-shaped rather than round, your baby is more likely to settle in a back-to-back position at the widest part of your pelvis. This is because he can rest his head more easily in this position.

Lifestyle may be another factor. It seems that Western (or urban) women are much more likely to have posterior babies than women in the developing world, who work manually in fields, or who squat to cook or eat. It's easy to understand why.

When you relax on a comfortable armchair watching TV, or work at a computer for hours, your pelvis is tipped backwards. This encourages the heaviest part of your baby (the back of his head and his spine) to swing round to the back. In this position, he'll end up lying against your spine.

If you do a lot of upright activities, your baby is more likely to go down into your pelvis in an anterior position, because your pelvis is always tipped forwards.

How can I help my baby into an anterior position?

You may have heard about a technique called optimal foetal positioning (OFP). This is a way of encouraging your baby into an anterior position by changing your posture, particularly when you're sitting down. Keep in mind that you're trying to tilt your pelvis forward rather than back, so, if you're sitting, check that your knees are always lower than your hips.

Try the following:

• Check that your favourite armchair doesn't make your bottom go down and your knees come up. If it does, try turning the chair round, kneel on the seat pad and lean forwards over the back of the chair.

• Scrub the floor! Our old granny used to say that washing the kitchen floor was a good way of preparing for labour. They were right - when you're on all fours, the back of your baby's head swings to the front of your belly.

• Take regular breaks and move around if your job involves a lot of sitting.

• Sit on a cushion in your car to lift up your bottom.

• Watch TV leaning forward over a birth ball.

Don't worry about getting your baby into the right position when you lie down to sleep. When you're lying down, your baby is not being pushed down into your pelvis. However, lying on your side rather than your back is the best position for sleep in late pregnancy.

Can I really make my baby get into the right position for birth?

There's nothing new about trying to get your baby into a good position. Reports of "maternal posturing" go back to at least the 19th century. It's known today as optimal fetal positioning (OFP) because of a midwife called Jean Sutton who publicised the technique in the 1990s. She advised pregnant women to get into upright and forward-leaning postures as often as possible in later pregnancy.

Some midwives and doctors have questioned whether it really works or just gives pregnant women something else to worry about. So far, studies into OFP show that adopting a hands and knees position for 10 minutes, twice a day, towards the end of pregnancy can help move your baby into an anterior position in late pregnancy.

Unfortunately, it doesn't seem to have an effect on how your baby lies at birth. Sutton recommends trying to stay in upright or forward postures regularly in every-day life, rather than for short bursts.

If you try OFP during pregnancy but your baby stays in a posterior position when labour starts, it may be because of the shape of your pelvis rather than your posture.

How can I improve my baby's position during labour?

If your baby is in a posterior position when labour starts you can still use upright or forward postures to try to help your baby to turn and to relieve your pain. It's common for babies to change position during labour and most babies get themselves into an anterior position by the pushing stage, no matter what position they were in at the start of labour.

Sometimes women have niggly pains for several days before labour really starts. This can be wearing, but the pain might be a sign that your baby is trying to turn into an anterior position. The best way to cope is to:

· try to get plenty of rest at night;

· during the day, remain upright and active;

· lean forwards during contractions;

· eat and drink regularly to keep up your strength;

· try to stay relaxed and positive.

You may find that the best posture to labour in is on all fours. In this position, your baby drops away from your spine, helping to relieve backache and hopefully helping him to turn, too.

When you're in actual labour, try to:

• Stay upright for as long as possible.

• Lean forwards during your contractions – use a birth ball, bean bag, your husband or the bed to lean on.

• Ask your birth partner to massage your back.

• Rock your pelvis during contractions to help your baby turn as he passes through the pelvis.

• Don't stay sitting in a chair or on a bed in a leaning-back position for too long.

• Try not to have an epidural if you can, as epidurals may increase the chance of your baby being in a posterior position at birth. Epidurals also make having an assisted birth more likely.

• If you get exhausted during labour, lie on your left side, as your pelvis can still expand to give your baby space to turn while you are resting.