Why You Shouldn't Sleep on Your Back While Pregnant

Pregnant woman asleep in bed.
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There are a lot of dos and don'ts in pregnancy. Sometimes the list begins to feel endless. The truth is, there are certainly some things that are truly potentially harmful and others that aren't really worrisome. There are also things that you can actually do something about, while others you can't do much to alter the process or outcome. The good news is that the position that you sleep in is something you can adjust!

Why Back Sleeping Could Be Problematic

During pregnancy, you will often hear that sleeping on your back is a bad idea. The reason has to do with your anatomy. When you lay on your back after about the fourth month of pregnancy, the weight of your pregnant uterus can decrease the blood flow in the vena cava, the vein that brings blood from the lower part of your body to the heart. If this were to happen, there is a risk of decreasing the blood flow to your uterus and baby.

The vena cava runs slightly to the right of your spine. This is why you may hear that laying on your left side is the best option in pregnancy. The key is really not lying on your back, either side is usually fine. So if you happen to prefer the right side, it is not a big deal. Most pregnant people wind up shifting from side to side through the course of the night.

So what happens when you wake up in the middle of the night and you're laying on your back?

First of all, don't worry about it. Just roll over onto a side or prop your body with a pillow to turn you one direction or the other. It is said that the average person rolls over more than 25 times in a night.

One pregnant mom said, "Everyone kept telling me how horrible it was to sleep on your back.

I tried to avoid it but would wake up on my back about once a week. My midwife finally convinced me that it wasn't going to hurt the baby. Maybe I was waking up to help me move. Who knows, but I decided to give up worrying about it."

Will a Pillow Help?

Using pillows between your legs while you sleep can be more comfortable. This can also help you prevent back pain while you sleep from strain placed on your back. It can also help you remember not to roll over on your back, even when you are asleep. You can also use a pillow behind your back as a reminder to not roll over, when it's there, if you feel it, you stop rolling, even if you're fast asleep.​

Any pillow will work, but there are special pillows made for pregnant women. They may come in different shapes and sizes. Choose the one that works for you, even if that is simply a regular pillow. The nice part is that the extra support behind your back can help provide added support on your back and hips for some moms.

If you are really concerned about your sleeping position, I would recommend that you talk to your doctor or midwife. They can help you understand what's going on and how to quantify the risk or non-risk to your baby. Don't lose more sleep over this position than you need to lose.

Many pregnant women already suffer from insomnia. Certainly, positioning can play a part in how well you do or don't sleep. There are many different ways to deal with insomnia that can be used no matter what your sleep position is at night. "Thankfully," says Rosie, "I wasn't worried about it as much as I was worrying about sleep in general. Eventually, you get too tired to care."


American College of Obstetricians and Gynecologists. Back Pain During Pregnancy. January 2016.

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