During pregnancy, you may find yourself wrestling in bed trying to get comfortable before falling asleep. Unfortunately, your regular sleeping positions may no longer work for you during pregnancy – especially if you typically sleep on your back.
I normally advise my patients to try sleeping on their side at around 20 weeks of pregnancy, when a pregnant person’s belly really starts to expand.
When you lie belly-up, the weight of your uterus can compress a major blood vessel, called the vena cava, a large vein that runs up the right side of your vertebral column and carries deoxygenated blood from the lower and middle body to the heart. Compressing this can disrupt blood flow to your baby and leave you nauseated, dizzy and short of breath. Back sleeping can also constrict the aorta, blocking off the main blood supply to your body and placenta.
What about sleeping on your stomach?
Sleeping on your stomach is fine in early pregnancy—but sooner or later you’ll have to turn over. Generally, sleeping on your stomach is OK until the belly is growing, which is between 16 and 18 weeks. Once your bump starts to show, stomach sleeping gets pretty uncomfortable for most women. But avoiding your tummy isn’t just about what feels good—it’s also for safety reasons. Sleeping on your stomach has the same negative effects as sleeping on your back.
Switching up your sleep
Changing the way you sleep can be tricky, and it’s common to change positions during the night. As the stomach expands, sleeping on the back becomes more uncomfortable. Because of this, most women naturally shift to a different sleeping position. However, if you need help adjusting to side-sleeping, try slipping pillows between your knees and under your belly to make it more comfortable. If you still can’t comfortably make the switch to your side, use pillows to prop yourself into an incline, as sleeping on your back at a 45-degree tilt can prevent a lot of the compression.
What if I wake up on my back or stomach?
Don’t stress out over occasionally rolling over onto your back at night or waking up on your back. Your body would let you know if your baby was in any real danger of not getting enough oxygen – you’d feel nauseated and breathless long before your baby would have a problem. If you continue to wake up on your back or stomach, ask your partner to check on you. If they wake up and notice you on your back, they can gently move you back to your left side.
More research needs to be done to determine any conclusive risks and, until then, it's best to follow the instructions of your doctor and organizations like the American Pregnancy Association and the American College of Obstetricians and Gynecologists.
Plus, you need your rest now more than ever -- let's not give you one more thing to keep you up at night.
Michael Cackovic is a maternal fetal medicine physician at The Ohio State University Wexner Medical Center.