Sleeping on your left side is thought to help make sure that plenty of blood and nutrients reach your placenta and baby.

Why shouldn’t you sleep on your back when pregnant?

Going to sleep on your back during the last 3 months of your pregnancy may increase your risk of having a stillbirth, research suggests.

We know that statistics about increasing the risk of stillbirth can sound scary, so it’s important to remember the risk of stillbirth is still very small. According to the Health Canada, 1 in 200 births ends with a stillbirth and a stillbirth can happen for all sorts of reasons. Sometimes, there’s just nothing anyone can do, or could have done, to prevent it.

The UK MiNESS study, conducted by the Tommy’s stillbirth research team in Manchester and published in the British Journal of Obstetrics and Gynaecology (BJOG) confirms the findings from other studies carried out by the Auckland researchers – and found that going to sleep supine (lying on your back) can double your overall risk of late stillbirth (after 28 weeks of pregnancy), independent of other common stillbirth risk factors.

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

Midwife Anne Richley agrees with advice that says sleeping on your back after around 16 weeks can be uncomfortable and make you feel faint. Towards the end of pregnancy, as your bump becomes heavy, Anne suggests it might be more comfortable to prop yourself up with pillows so that you are almost in a sitting position. This can also help with pregnancy heartburn.

What should I do if I wake up on my back?

Don’t panic! One really important thing to clarify is that the research findings refer to the position you go to sleep in, not the position you wake up in.

The position you fall asleep in is the most important position, say researchers, because it’s where you’ll have the longest, ‘soundest’ sleep on the night.

Don’t lie awake worrying about what position you should be in or be alarmed if you wake up on your back, you’ll naturally change position before it causes you or your baby any problems.

So, if you go to sleep on your left side, there’s no need to worry if you find you’ve rolled over on to your back, or to another position, in the middle of the night. Pregnant women may decide to try sleeping on their left side, but should not unduly worry if they wake up and find they have changed position.

Above all, it’s important not to let disturbed sleep worry you. It won’t harm your baby.

Is it safe to sleep on your right side?

There is ongoing research into safe sleep positions during pregnancy following the same small Auckland study which linked lying on your back or right side with an increased risk of stillbirth.

The study showed more research was needed and did not conclusively prove that sleeping position affects the risk of stillbirth. The risk of stillbirth is very low, regardless of sleep position.

So how do Baby & Toddler moms sleep in pregnancy?

“I was a tummy sleeper,” says Luna, “but as I got bigger in the pregnancy this obviously wasn’t an option, and neither was sleeping on my back. I literally used to flip from side to side with a pillow between my legs supporting my bump. I must have looked very interesting.”

Sarah says, “I would consider looking into a pregnancy pillow – they are seriously fab. My husband can’t wait for me to have this baby so that he can use it!!”

And we’ll give Jennifer the last word, because we reckon she’s got a good point: “Sleep in pregnancy… is a myth!”