Is It Really All That Bad To Sleep on Your Back While Pregnant?

Since the moment you got that positive pregnancy test, you’ve been painstakingly conscientious to have a healthy pregnancy.

You keep your prenatal appointments. You take your vitamins like clockwork. And you don’t change the kitty litter. (Heck, who are we kidding? Someone else can do that one permanently!)

But then, you woke up this morning and had a groggy (and panicked!) realization: You were sleeping on your back.

Isn’t that a no-no? Isn’t that what every single pregnancy book and baby forum you’ve read has advised against? But how bad is it really?

Take a deep breath. While sleeping on your back while pregnant isn’t ideal, it’s not likely going to do any lasting harm.

So, what’s behind all those warnings about back-sleeping during pregnancy? Ob/Gyn Salena Zanotti, MD, explains.

The concern with sleeping on your back during pregnancy

Why does all the pregnancy advice you’ve read discourage back-sleeping?

Here’s the deal:

As your uterus gets larger (usually by the time you’re 20 weeks along ― that’s five months), it’s big enough that it can put pressure on your aorta and inferior vena cava if you’re lying on your back. That’s the big blood vessel that brings blood flow back to your heart.

“The thought is if you have anything large, like an expanding uterus, that’s pushing against the blood flow return, you’ll have less blood flow to your heart,” Dr. Zanotti explains. “That can mean less blood flow for yourself and for the developing fetus.”

What can that actually do?

Researchers in one study found that there was a potential increased risk of stillbirth for those who slept the entire night on their back.

But before you panic, Dr. Zanotti points out that this study and others were small, not randomized, and shouldn’t be taken as definite proof.

For instance, the studies looked at pregnant women who spent all night on their backs. They never shifted positions and they didn’t get up to use the bathroom. Which isn’t usually the case.

“In pregnancy, most of the time you don’t sleep the entire night without getting up — even if you wish you could,” notes Dr. Zanotti.

Plus, a healthy pregnancy is a combination of myriad factors. That makes it tough to say any one thing causes stillbirth or most other pregnancy risks.

“A lot of people who are back-sleepers may also snore or have sleep apnea. That’s where these studies are faulted. You can’t weed out all those things,” Dr. Zanotti reassures.

What’s more, as you get further along in your pregnancy and your uterus is big enough to put pressure on your blood vessels, your body will let you know if you’re not in a good position.

You may feel light-headed or uncomfortable if you’re on your back for long periods of time.

“Oftentimes, your body is going to tell you something isn’t right, and that will make you move around,” Dr. Zanotti reinforces. “So, if you’re on your back and having a little trouble breathing or maybe your heart is beating faster, it’s your body’s way of saying you need to roll over on your side. Listen to that.”

How long can you lay on your back when pregnant?

Dr. Zanotti says it’s OK if you find yourself on your back for a brief spell — like if you wake up on your back or lounge on your back while watching a TV show or movie.

“We do know that short periods of time ― even if you were on your back for an hour or two ― probably do no harm to your child,” she clarifies. “The hard part is we can’t really quantify exactly how much time is a ‘safe’ amount of time.”

Best sleeping positions for pregnancy

So, what should you do? After all, all that advice you read said you should get good sleep during pregnancy. How are you supposed to do that if you’re worried about rolling on your back all night?

While it’s sensible to be cautious, Dr. Zanotti says it’s also important to recognize that you already have enough worries on your mind. And how you sleep doesn’t necessarily need to be at the top of that list.

That said, there are some best sleep practices you can try out.

Off your belly

In your first trimester or so, sleeping on your belly is just fine. But as your bump grows, chances are, it won't be the most comfortable position.

Your body will let you know when it’s time to give up sleeping on your stomach.

Prop yourself up

After 20 weeks of pregnancy, you’re better off not spending the entire night flat on your back. But propping yourself up with a pillow to sleep can help you get comfortable and keep your blood flowing.

Try putting a pillow between your back and the mattress. That way, even if you do roll over, you’re still on a bit of an incline.

“As long as you’re not flat on your back, you’re going to be fine,” Dr. Zanotti advises. “Even if you can be on a 20- to 30-degree angle, that’s going to relieve any potential pressure on your inferior vena cava. I think most people, even if they were back sleepers, can be comfortable sleeping with just that bit of an angle.”

Pick a side (any side)

Traditionally, Ob/Gyns have advised their patients to sleep on their left side. That’s because your inferior vena cava is on your right.

“The thinking was that if you slept on your right side, you could potentially compress the blood flow,” Dr. Zanotti shares.

Today, the evidence shows that if you’re truly on your side, you’re still going to get good blood flow, regardless of the side you’re on. So, most experts say it’s OK to sleep on either side.

“The left side’s probably the absolute ideal,” she adds. “If you like your left side, wonderful. If you’re a right-sided sleeper, you’re fine that way, too.”

And if you need some help getting cozy, a pillow behind your lower back can help keep you in position.

Getting a good night’s rest is important. For you and the developing fetus. So, snuggle up. Get comfortable. And dream sweet dreams.