The value of HCG on day 42 of pregnancy should not be lower than 1000 IU/L. If it is too low, you should be alert to the possibility of miscarriage, and you should exclude the possibility of ectopic pregnancy. It is recommended to have an ultrasound examination in time to know whether there is an ectopic pregnancy, so that the embryo development can be detected and solved in time. In the early stages of pregnancy, the fetus is easily affected by external factors, so you should pay attention to avoid contact with toxic and harmful substances, and try to avoid getting cold and flu to prevent the possibility of fetal malformation. Most women will have early pregnancy reactions on the 42nd day of pregnancy, such as nausea, vomiting, anorexia and other symptoms. It is recommended to eat less and more meals, and choose to eat light and easily digestible food, which can effectively reduce the symptoms of gastrointestinal discomfort. Avoid eating too much greasy and indigestible food, and pay attention to ensure the intake of calories and high-quality protein, which will help the growth and development of the fetus.