Left-side sleeping may be particularly beneficial for the circulatory health of individuals who are pregnant (via CNN). During pregnancy, the fetus places upward pressure on the organs. We already know that positioning our weight on our right side as we dream reduces blood flow, but the additional stress from the organs during pregnancy may further enhance this restriction, potentially affecting the fetus and the pregnant person.

However, it’s important to note that some studies have found no such relationship between sleeping position during pregnancy and circulation-related health risks to the baby. In a 2019 study published in Obstetrics & Gynecology, researchers found that back-sleeping or right-side sleeping during the early and middle stages of pregnancy was no more likely to result in complications than left-side sleeping or alternate sleeping positions.

That being said, sleeping on one’s left side during pregnancy may still offer some unique benefits, such as reduced swelling in the lower extremities, reports the Sleep Foundation. For pregnant individuals wanting to stick to their left side, it’s advised to do so with your knees bent. Talk to your doctor should you have any questions or concerns.