Sleeping on your left side during pregnancy is important for proper blood flow.
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Why Do You Have To Sleep On Your Left Side During Pregnancy?

It’s actually really important.

Pregnancy is a wonderful and beautiful thing that can, unfortunately, also be ridiculously uncomfortable, especially when it’s time to sleep. You toss and turn until you finally find a sweet spot with your right arm propped under your belly. Then, you remember that your doctor told you to sleep on your left side during pregnancy. Ugh.

Though it can certainly be a challenge to get comfortable enough to fall soundly asleep when you’re pregnant, sleeping on your left side is one of those pregnancy recommendations that’s actually pretty important.

Why Sleeping On Your Left Side Is Recommended During Pregnancy

“Sleeping on your side is great for your blood circulation during your pregnancy,” Paul Osterdahl, D.O., an obstetrician with Inspira Medical Group, tells Romper. “Some physicians recommend sleeping on your side, which optimizes blood flow to the placenta, in turn providing a consistent flow of nutrients and oxygen to your baby. Good blood circulation has many benefits and may lower instances of varicose veins, hemorrhoids, and leg swelling.”

Specifically, many practitioners suggest that women sleep on their left side when pregnant to support blood flow through the main vein that carries blood back to the heart from the lower body called the vena cava. At a minimum, it’s recommended to avoid sleeping on your back if at all possible. Doula and birthing expert Sara Lyon tells Romper that when you don’t sleep on your side during pregnancy, “The weight of the fetus can compress the inferior vena cava, reducing blood flow between the heart and the fetus.”

“There is a very small chance that this compression is severe enough to cause problems for mom and baby,” Lyon continues. “Additionally, the liver lives on your right side, and plays an important role in reducing swelling in the hands and lower legs. Taking the fetus’ weight off the liver allows this large organ to function more effectively.”

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While sleeping on your left side is recommended and important, the main goal is to avoid the complications that can come from sleeping on your back with your intestines and vena cava potentially compressed, which Osterdahl says can include backaches, hemorrhoids, indigestion, poor circulation, and blood pressure changes. “That being said, most pregnant people find sleeping on their backs increasingly uncomfortable as their bellies grow and cannot comfortably sustain that position for extended periods of time.”

How To Find A Comfortable Sleeping Position During Pregnancy

If you find yourself tossing and turning to get into a comfortable sleeping position, the best thing to do is listen to your body. “Your body will largely tell you what’s comfortable,” Lyon explains. “For example, if your vena cava is compressed, you will feel nauseous and dizzy, like you’re about to faint, but you’re already laying down. The sensation is uncomfortable enough to wake you up and you can roll onto your side at that point to alleviate the symptoms and refresh the blood flow quickly.”

The same can be said about sleeping on your stomach, Lyon continues. “It will feel like you’re sleeping on a water balloon and you will instinctively prefer sleeping on your side or back at that point. Sleeping on your side will always be safe, so plan your pillow set-up and snooze.”

If you’re feeling uncomfortable, you can try rearranging your pillows or doing some light stretches to find what works best for you so that you can actually rest. “It’s completely normal to change positions while you’re sleeping. Although most physicians agree that the left or right side is ideal, it’s most important to find a position that is comfortable for you,” Osterdahl tells Romper.


Sara Lyon, birthing expert, doula, author of The Birth Deck and You’ve Got This: Your Guide to Getting Comfortable with Labor

Paul Osterdahl, D.O., OB-GYN at Inspira Medical Group Obstetrics And Gynecology Mullica Hill