Side Sleep – What does it mean?

by Lindsey J. Wimmer, RN, MSN, CPNP, CPLC

Star Legacy Foundation is honored to be partnering with Tommy’s in the UK and Still Aware in Australia to promote worldwide information about safe sleep positions during pregnancy. Help us share the new video published about this topic.

As with any new information or research, there are many questions that come to mind. Research will never provide a perfect answer for all situations, and this is not a ‘magic bullet’ that will end all stillbirths. But, here is what we can learn from the data in these studies.

What do the studies say?

There are now 4 studies from around the world that have had the same finding – women who sleep on their backs during the 3rd trimester have a higher rate of stillbirth than women who sleep on their sides. The numbers vary from 2-8 times the risk of stillbirth.  While these are newly released studies (back to 2011), this is a concept that Labor and Delivery nurses have understood and used for decades. It is reasonable to think that positions that help a mother and baby during labor might be helpful during the 3rd trimester also.

What does that mean?

Researchers have found that women who had a stillbirth were more likely to have slept on their backs during the final weeks of their pregnancies than women who had live births. This simply identifies supine (back) sleeping as a risk factor for stillbirth. Like many risk factors, it does not mean that you have to sleep on your back to have a stillbirth, nor does it mean that if you slept on your back you caused your stillbirth. It also does not mean that every woman who sleeps on her back will have a stillbirth, or that every woman who sleeps on her side will not have a stillbirth.

We can look at other risk factors in a similar way. For example, we know that women who are over 35 years old have a higher risk of stillbirth. Women in this age group don’t cause a stillbirth with their age, and they are not guaranteed to have a stillbirth because they are over 35. Women under 35 have a lower risk, but they could also have a stillbirth.

What is exciting about the sleep studies is that it points to a modifiable risk factor that is relatively easy to change, doesn’t cost anything, and doesn’t cause harm.

The studies indicate that if all women start sleeping on their sides during the 3rd trimester of pregnancy, the stillbirth rate could drop by 10%! That does not mean it will prevent all stillbirths, but it can make a significant difference for thousands of families.

How does this work?

Researchers are still working on this part to know for sure! The most common theory is related to the pressure the uterus p

uts on the mom’s circulatory system and inferior vena cava late in pregnancy. Laying on her side can reduce compression of the inferior vena cava allowing more blood to return to her heart and subsequently to the baby.

This hypothesis is the reason why sleeping on the left side is suspected to be best. This data is a little less clear from the current studies. What is clear is that either right or left side sleeping seems to reduce the risk of stillbirth compared to back sleeping.
It is also hypothesized by many researchers that this compression is not enough to cause distress for an otherwise healthy baby without any other issues. It is likely a problem when it takes away a compensatory mechanism the baby was using to overcome other issues.

What if I wake up on my back?

Many women are worried about if they go to sleep on their side but wake up on their back. Studies found that the risk was reduced by women settling to sleep on their side regardless of what position they woke up. The position we go to sleep in is how we sleep the majority of the night. If you do wake up on your back, just roll over to your side before you settle back to sleep.

Some suggestions to help women stay on their sides are to use pillows, body pillows, or a wedge. Another option is to tie a tennis ball into the back of a sleep tshirt with a rubberband that will gently remind her to stay on her side. There are several studies currently trying to identify if devices that help women stay on their sides are helpful, and if so, which method is best.
Many women find it hard to sleep on their sides or get sore after sleeping on one side. The use of pillows to lean against, prop up a hip, or elevate the woman’s head can be helpful in these situations.

Why should we talk about sleep?

It is always exciting when new information is available that can help more families take home a happy, healthy baby! Unfortunately, many families are not taught about risk factors before they experience a poor outcome. We want all women and families to have any information they might need to increase the chances that their baby stays healthy.

We want women to learn about risk factors for poor outcomes so they have an opportunity to reduce the modifiable ones and proactively manage any others. Side sleep can be viewed like other advice during pregnancy such as take a prenatal vitamin, monitor fetal movement, get regular prenatal care, stop smoking or using other recreational substances, eat a healthy diet and maintain a healthy weight, etc.

It can be heartbreaking for women who have experienced a stillbirth to realize they didn’t have this information while they were pregnant. We understand this reaction and it is completely normal. We also want these women to know that they can only hold themselves responsible for what they knew. It may be little comfort, but it is also why we want to make sure that every pregnant woman has all the information they need. We hope you’ll help us spread the word!

Because every pregnancy

deserves a happy ending.

For more information, visit us  or send your questions to [email protected].