When to Sleep on Your Side During Pregnancy

By Bailey Miller
Reviewed by Alyssa Quimby, M.D.
May 07, 2024

Do you sleep on your back? During pregnancy, you’ll need to get used to a new position: side sleeping.

Sleeping on your back during late pregnancy can put pressure on your spine and back and affect how much blood is flowing to your baby, according to the American College of Obstetricians and Gynecologists. This can cause discomfort and increase risks for you both.

Some sources say to start sleeping on your side during the third trimester to prevent risk of stillbirth. Others say the second trimester is even better so you can get used to it. Try around week 20, when your uterus will likely start to grow up to your belly button level. That way, you can be as comfortable and safe as possible as your belly continues to get bigger.

If you’ve been a back sleeper your whole life and can’t imagine making the switch to side sleeping, try placing a pillow between your knees and under your belly, using a wedge pillow under your back, or using a full-body pregnancy pillow for extra support. These tricks may help you feel more comfortable and supported as you sleep through the night.