when should i stop sleeping on my back during pregnancy

You should stop sleeping on your back during pregnancy starting around 20 weeks (the second trimester). During this time, the growing uterus can put pressure on major blood vessels (like the inferior vena cava), which may reduce blood flow to your heart and fetus. This can potentially cause low blood pressure, dizziness, and affect fetal growth. Most experts recommend switching to sleeping on your side, preferably the left side, as this position promotes better circulation for you and your baby. This advice is especially important from the third trimester (after 28 weeks), when sleeping on your back has been linked to an increased risk of stillbirth in multiple studies. Side sleeping is considered safer throughout the later stages of pregnancy, including naps and returning to sleep after waking up.