Any woman who has been pregnant knows sleeping is not particularly easy, especially during the last trimester. In fact, it can be nearly impossible those last couple of months and not for lack of trying.
There are tons of books, hacks and old wives tales pregnant women are told that will supposedly help them get a good night's sleep. Doctors have a new idea for mamas to be when it comes to sleeping, lay on your left side only. It is not merely a suggestion either; there is a reason doctors are now telling pregnant women not to sleep on their right side.
As the fetus grows, it puts more discomfort on the mama's body, kicking her insides and most commonly sitting on the bladder. However, the left side sleeping is not just about comfort, even though it is said to be the most comfortable position for pregnant women, there is an actual medical reason for this recommendation.
Johns Hopkins University School of Medicine professor Dr. Grace Pien explained to Live Science the reason is that a large vein called the inferior vena cava runs along the right side of the mother's spine. The vein is vital because it carries blood from the bottom half of a person body to the heart. If this vein is compressed it could be damaging. When a pregnant woman sleeps on her back, the fetus is more likely to compress the vena cava.
Although Pien did suggest there is no research proving the left side is better to sleep on than the right side, considering the vein is on the right side of the spine, it makes sense to have the fetus more on the left side to keep the vein from becoming compressed. Should the vena cava get compressed, it could cause blood flow issues. The reason may not physically help you get a better night's sleep, but it will at least put your mind at ease that you are avoiding a potential complication.
Does this mean women should not sleep on their back at all? Not necessarily. It is essential that both the mother and fetus are comfortable. However pregnant women should be cautious of how much time they spend sleeping on their backs. Of course, consult a doctor before making any decisions regarding the best ways to sleep while pregnant to figure out what will be the best for you and your unique situation.