Is sleeping on the right side at 17 weeks of pregnancy harmful to the fetus?

Occasionally sleeping on the right side at 17 weeks of pregnancy does not affect the fetus. However, frequently sleeping in this position can have adverse effects. It is recommended to rest on the left side during the middle and late stages of pregnancy. The detailed explanation is as follows:

1. No adverse effect

At 17 weeks of pregnancy, abdominal enlargement is not yet significant. Occasional right-side resting generally does not harm the fetus, and alternating between left and right sides is acceptable.

2. Potential adverse effects

If a pregnant woman frequently sleeps on her right side, it may worsen the natural rightward rotation of the uterus, placing ligaments and membranes that support the uterus in a state of tension. This can impair blood supply to the uterus. As pregnancy progresses, this position may compress the inferior vena cava, reducing venous return to the heart, leading to insufficient placental perfusion, fetal hypoxia, and even fetal distress in utero.

It is advisable during pregnancy to rest primarily in the left lateral position. While occasional right-side lying is acceptable, prolonged periods in this position should be avoided.