It is normal for women not to have severe vomiting in the first trimester of pregnancy because some women do not have severe vomiting in the first trimester of pregnancy due to the difference in their individual constitution. After pregnancy, the level of human chorionic gonadotropin in a woman’s body rises significantly, which affects the body to a certain extent, thus causing the phenomenon of pregnancy vomiting. Most pregnant women experience vomiting when they are about six weeks pregnant, and the early pregnancy reaction will gradually disappear after twelve weeks of pregnancy. In early pregnancy, you should eat a light diet and avoid oily and spicy foods. Due to individual differences, a few pregnant women may not experience pregnancy sickness until delivery, so as long as the blood test and ultrasound examination are normal, there is no need to worry too much, which is normal. However, it is also necessary to exclude some abnormalities, such as fetal termination, after the embryo stops developing, the level of human chorionic gonadotropin decreases, resulting in pregnant women do not experience pregnancy sickness. In short, regular obstetric examinations should be conducted during pregnancy to avoid affecting the health of the pregnant woman and the fetus.