Patient's question:
Hello, doctor! I am currently two months pregnant. Should I also choose to sleep on my left side? Under normal circumstances, how many months must one sleep on their left side to avoid affecting the fetus?Doctor's answer:
Hello: There are basically three sleeping positions for humans: supine, lateral, and prone. For the average person, as long as they sleep comfortably, it doesn't matter what position they choose. However, for pregnant women, things are not that simple.In the supine position, the enlarged uterus compresses the inferior vena cava, affecting blood circulation and causing edema or varicose veins in the lower limbs and external genitalia. It also reduces the amount of blood returning from the lower limbs to the heart, leading to brain ischemia and hypoxia. Therefore, pregnant women should never sleep on their backs.
The prone position is rarely adopted by normal individuals. Asking a pregnant woman to lie flat with her large belly is both unrealistic and impossible.
Lateral sleeping positions include right lateral and left lateral. In the right lateral position, the uterus may rotate to varying degrees to the right. This tension can strain the ligaments and mesenteries that maintain the normal position of the uterus. The blood vessels in the mesentery are stretched, affecting the blood supply to the fetus and causing chronic hypoxia. In severe cases, it may even lead to fetal asphyxia or death.
So, the only option for pregnant women is the left lateral position. In fact, the left lateral position is the best sleeping posture for pregnant women in the late stages of pregnancy. This position can help the right-rotated uterus return to a straight position, reducing the risk of abnormal fetal position and delivery complications. It also avoids compression of the inferior vena cava by the uterus, increases the amount of blood ejected by the heart, reduces edema, improves blood perfusion to the uterus and placenta, and is beneficial for reducing preterm labor, avoiding uterine compression of the kidneys, and promoting fetal growth and development for a healthy birth.