Nausea is an early symptom of pregnancy that starts at around 6 weeks of pregnancy and disappears on its own at around 12 weeks of pregnancy, but there are individual differences and some women may experience delayed vomiting until after 12 weeks. The main cause of vomiting is the increase in chorionic gonadotropin levels and the instability of thyroid hormone levels during early pregnancy, which reduces the secretion of gastric acid and prolongs gastric emptying time, causing nausea and vomiting. Most women with pregnancy vomiting and HCG secretion peak time coincides, 6-8 weeks HCG peak, 10 weeks after the maintenance of stability and transition to 12 weeks after the drop to a minimum, and to the lowest level to maintain to the end of pregnancy, so pregnancy vomiting is generally in 12 weeks or so end. However, pregnancy sickness is also related to the pregnant woman’s own excessive mental tension, anxiety, worry and poor living environment and economic situation. During the period of pregnancy vomiting, pay attention to a light diet, small and frequent meals, avoid the intake of stimulating food, if pregnancy vomiting is more severe, if necessary, you can take a small dose of vitamin B6, can reduce the symptoms of pregnancy vomiting.