Suddenly nausea again at 13 weeks of pregnancy may be a normal physiological phenomenon. Most of the early pregnancy reaction at about 12 weeks of pregnancy, can disappear on their own, but there are some people who have a more serious pregnancy. In the 13th week of pregnancy and have nausea, vomiting phenomenon, which consider the early pregnancy reaction impact. After pregnancy, the body’s hormone levels increase, and these hormone levels act on the gastrointestinal tract. It is possible to cause spasms in the gastrointestinal tract, resulting in nausea and vomiting. Hormone levels in the body are different depending on the individual’s physical condition. Pay attention to rest, do a good job of obstetric examination, fetal development in all aspects of normal can be. Diet during pregnancy, pay attention to increase nutrition, do not worry too much, some people may have pregnancy vomiting reaction throughout pregnancy. Specific discomfort, to go to the hospital obstetrics and gynecology consultation.