Level 1: How early in pregnancy does morning sickness start to appear? Morning sickness is an uncomfortable symptom experienced by many pregnant women, usually early in pregnancy. Specifically, about 70% of pregnant women will start to experience morning sickness around 6 weeks into pregnancy, and around 10 weeks, most pregnant women\’s symptoms of morning sickness will gradually reduce or disappear. Level 2: Why does morning sickness occur? Currently there is no understanding of why