Stillbirth risk four times higher if pregnant women sleep on back - study

  • 14/06/2017

Women are four times more likely to have a stillborn baby if they sleep on their back in the last trimester, new research has found.

The University of Auckland study says the risks are higher after 28 weeks of pregnancy. Author Lesley McCowan says the simple method of sleeping on your side could reduce late still-births by around nine percent.

"When you lie on your back in late pregnancy, the weight of the pregnant uterus compresses a big vein in the abdomen called the inferior vena cava, and that reduces the blood going back to the heart and it reduces the blood supply going to the womb."

Professor McCowan says sleeping on one's side and turning over when sleeping is an easy way for pregnant women to reduce the risk.

The recent Multi-Centre Stillbirth Study was conducted in seven New Zealand District Health Board areas comprising two-thirds of all New Zealand births (Waitemata, Auckland, Counties-Manukau, Waikato, MidCentral, Capital & Coast, and Canterbury).
In this case-control study 164 women experienced a stillbirth at or beyond 28 weeks' gestation in their current pregnancy, and 569 were pregnant with a live baby, allowing comparisons to be made between mothers with stillborn infants and those with ongoing pregnancies.

Pregnancy and newborn death support group Sands says it could potentially save 15 babies a year.

Sands spokesperson Rebekah Gray says the research is an easy way to help prevent families from losing a child.

"Any kind of one where we can prevent even just one family going through what some of our families have gone through is amazing.

Every year in New Zealand, around 160 babies are stillborn in the last three months of pregnancy.

Recommendations from the research:

  • Is it best to go to sleep lying on my left side rather than my right side?

Many pregnancy web sites suggest that sleeping on the left side is best. One study reported that the left side may be better for baby than the right but two further studies have shown no difference between left and right sides. 

  • What do I do if I wake up on my back in the night?

Don’t worry - this is normal. Just settle back to sleep on your side.

  • Why is it that going to sleep position is important rather than the position I wake up in?

The position that you fall asleep in is the one in which you have the longest and soundest sleep and may therefore have more impact on the baby.

  • What can I do to increase my chance of staying on my side during the night?

A pillow behind your back may be helpful.

  • What about having a sleep during the day?

A lot of pregnant women have a day time nap. If you nap during the day settle to sleep on your side.