Sleeping on your either side can help give you and your baby optimal blood flow. Doctors may recommend not sleeping on your back or stomach after a certain point in your pregnancy.

From steering clear of your favorite contact sports to shunning certain foods, the do’s and don’ts list of pregnancy can be a bit overwhelming.

And as your belly grows week after week, you may be adding sleep positions to your list of concerns.

Here’s some help wading through the myths and facts related to sleep positions during pregnancy and how the way you rest affects the health of your baby and you.

Related: 11 foods and beverages to avoid during pregnancy

Doctors generally recommend sleeping on your side during pregnancy, especially as time goes on.

Why is this exactly? It boils down to blood flow. As the fetus gets bigger, there is greater chance of compression of the blood flow to the uterus.

However, doctors still continue to tilt patients when they are lying down during a cesarean delivery, commonly called a c-section, or when they are in labor with abnormal heart rhythms.

A 2019 review of medical studies suggests that sleeping on your back carries risks, but it doesn’t seem to matter whether you sleep on your right or left side.

These studies do have some flaws, though. Third trimester pregnancy loss is very uncommon. Therefore, there aren’t many cases from which to draw conclusions.

Additionally, it’s difficult to determine exactly when the fetus passed away and whether there were other factors involved. It can be challenging to pinpoint what is occurring in utero without monitoring.

The study did find, however, that there was an increased risk of stillbirth for back sleepers after 28 weeks.

There’s a lot of mixed data on whether lying flat on your back during pregnancy contributes to an increased risk of stillbirth.

A 2019 study of about 800 women for up to 30 weeks of pregnancy examined the sleeping positions of those who experienced stillbirths.

The researchers found no association between those who reported sleeping on their back or a non-left side sleeping position.

Currently, only a limited number of studies are available on this topic. More research is needed to be certain whether or not there is an association between stillbirths and sleeping positions up to 30 weeks of pregnancy.

Left side

Sleeping on your left side is often referred to as the “ideal” scenario during pregnancy.

Positioning yourself on the left side of your body allows for optimal blood flow from the inferior vena cava (IVC).

This large vein runs parallel to your spine on the right side and carries blood to your heart and, in turn, to your baby.

Sleeping on your left side also takes the pressure off your liver and your kidneys. This means more room to function properly, helping with swelling issues in your hands, ankles, and feet.

Right side

So, if the left side is ideal — should you avoid the right side? Not necessarily.

That 2019 review showed equal safety with sleeping on the left and right sides. There’s a slight risk of compression issues with the IVC when you sleep on the right, but it’s mostly a matter of where you’re comfortable.

A note about baby’s sex

You may have heard that your sleep side indicates the sex of your baby. This is just an urban legend. There are no studies to suggest that sleep position has any correlation to the sex of your baby.

Related: Can belly shape in pregnancy predict you’re having a boy?

If side sleeping isn’t your thing, here are some suggestions for how to make it feel more natural or at least comfortable.

If you’re especially concerned about your sleeping position, you may even ask your partner to check on you from time to time and help nudge you into a better position.

First trimester

Sleeping in any position is generally fine early on. But if you want to get into the habit of favoring your side, try simply slipping a pillow between your legs. This may ease discomfort in your hips and lower body.

And if you want to be a little, well, extra, you could consider getting an orthopedic knee pillow that’s made of memory foam.

Second trimester

As your belly grows, you’ll want to make sure your mattress is somewhat firm so your back doesn’t sag. If yours is too soft, you might consider slipping a board between your mattress and box spring.

You may also want to look into pregnancy pillows. They come in U or C shapes and wrap around your entire body to help with side sleeping.

You position the pillow so that it runs along your back and then hug the front while simultaneously slipping it between your knees.

Third trimester

Continue using a pregnancy pillow for support. If you find them a bit cumbersome with your growing belly, investigate wedge pillows. You can stick them under your belly and behind your back to keep from rolling.

If you simply can’t get used to sleeping on your side, try using pillows to prop your upper body at a 45-degree angle. This way, you’re not flat on your back and you take the compression off your IVC.

Alternatively, you can try elevating the head of your bed a couple inches with books or blocks.

Wondering if you can sleep on your stomach during pregnancy? You sure can — at least for a while.

Stomach sleeping is OK until you reach about weeks 16 to 18. At that point, your bump may be growing a bit bigger, making this position less and less desirable. It may feel a bit like you’re trying to sleep atop a watermelon.

Besides comfort, though, there isn’t much to worry about if you somehow find yourself on your stomach. The uterine walls and amniotic fluid protect your baby from being squished.

To make this position more comfortable, you may consider purchasing a stomach sleeping pillow. Some are inflatable and some are more like a firm pillow with a large cutout for your belly.

Whatever one you choose, the idea is that you get some shut-eye on your stomach while giving your baby (and you) plenty of room to breathe.

Related: How to kick insomnia in early pregnancy

Sleeping on your back is generally considered safe throughout the first trimester.

After that, you may have heard that studies link sleeping the whole night on your back to stillbirth. Before you get too worried, understand that the studies are small and there may be other factors like sleep apnea at play.

Nevertheless, these studies can’t be completely discounted. In the end, not sleeping on your back may lower your risk of stillbirth after 28 weeks by 5.8 percent.

Plus, there are other issues with sleeping on your back. This position may contribute to back pain, hemorrhoids, digestive issues, and poor circulation. It may also make you feel lightheaded or dizzy.

Should you worry if you wake up on your back in the middle of the night? Likely not — but it’s a good idea to try another position.

If you’re a solid sleeper (lucky you!) and often find yourself on your back, consider placing a wedge pillow behind you.

That way, when you try to roll onto your back, you’ll stop at an angle that will still allow blood to flow and nourish your baby.

Related: Your guide to sleeping on your back during pregnancy

There’s a lot you may worry about during your pregnancy. Your sleep position doesn’t need to be top of the list.

Doctors recommend resting on your side — right or left — to give you and your baby the optimal blood flow. Beyond that, you might try using some pillow props to get into the most comfortable position for you.

Soak in all the sleep you can before your baby is born. And consult with your doctor if you have other questions about which position is best.

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