Sleeping on back in pregnancy can cut the blood f low to baby

IT is a time in pregnancy when mothers-to-be are increasingly excited about the arrival of their baby.

But now experts have warned that going to sleep on your back in the final three months could harm your unborn child.

They say it may cut blood flow to the baby in the womb through the umbilical cord by 11%.

Women are already advised to sleep on their side to reduce the risk of stillbirth in the final three months. A study of 22 women asked them to lie on their backs for 20 to 25 minutes in a magnetic resonance imaging (MRI) machine.

It reduced blood flow in the umbilical cord by 11.2% on average. Oxygen reaching the unborn baby in the womb reduced by more than 6% compared to when the women lay on their side.

Doctors say that many stillbirths show signs of the baby having been starved of oxygen – and the findings shed light on how sleeping positions play a role.

Professor Anna David, of University College London, senior author of the UK-New Zealand study, said the findings ‘may partially explain why some women with an apparently healthy, normal-sized baby nevertheless suffer a stillbirth.

‘They confirm how the message to mums to sleep on their side in late pregnancy is very important for a healthy pregnancy.’

Women who go to sleep on their back, taking the weight of their bump, are believed to put pressure on a major vein carrying blood to the heart from the lower part of the body. This may lead to the heart pumping less effectively and less oxygen-rich blood being transferred to the baby.

The study of the 22 New Zealand women found they had substantially less blood flowing through the vein when on their back compared to when they were on their side. It was cut by almost a quarter in a major artery supplying blood to the womb.

Jane Brewin, of UK baby charity Tommy’s, said: ‘Going to sleep on your side is safer – if you wake up in a different position, don’t worry, just get back on to your side.’

‘Going to sleep on your side is safer’