Women are not being encouraged to move around during labour, even though it would make giving birth easier and less painful.

The National Childbirth Trust said 40% of women are not advised to adopt a more comfortable upright position instead lying on their backs or sitting on their bottoms.

Upright positions are used by women around the world, but in the West, women may not be encouraged to adopt them.

The NCT warns the design of labour rooms, and the tradition that doctors carry out examinations with the woman lying down, do not help.

It seems crazy that so many women are having longer, more painful and more difficult labours than they need to

Belinda Phipps, NCT

It is calling for maternity units to back its campaign to encourage women to move around during labour.

The NCT says standing up, sitting, or squatting to give birth reduces pain, shortens the length of the first stage of labour and results in fewer assisted births or caesareans.

It adds that the effect of gravity means the angle of descent is easiest for mother and baby.

Blood flow

Research has also demonstrated women who adopt upright positions for labour have less need of an epidural and have less chance of developing an infection of the womb.

If the woman is upright, the baby's head pushes on the cervix, aiding dilation.

It also encourages better blood flow to both the baby and placenta, reducing the risk of foetal distress.

Upright positions are also thought to maximise the space between the pelvic bones and allow the joints to flex slightly so the baby has more space to move.

Belinda Phipps, chief executive of the NCT, said: "It seems crazy that so many women are having longer, more painful and more difficult labours than they need to - just because they aren't aware of the benefits of being active during birth.

"Many women think that lying down is the usual way to give birth, but getting up and walking around is not only more comfortable, it can also shorten the length of labour."

Anxiety

But Dr Maggie Blott, a consultant obstetrician and gynaecologist at King's College Hospital, London, told BBC News Online: "There's no problem with moving around in labour. Women who are at low-risk are encouraged to do so.

"But a lot of women do not get one-to-one care from a midwife. They get very anxious about the pain and choose to have an epidural - so they can't move around."

She said women having their first baby were often very anxious.

"Women need better support in labour, so they don't go for intervention."