The first fetus is normal and the second fetus has chromosomal problems, which may be caused by abnormal differentiation process of fertilized eggs, chromosomal problems between husband and wife, and other factors. Before and after pregnancy should be strictly good eugenics examination, etc. The first fetus is normal, the second fetus chromosome is not necessarily normal. When the fertilized egg of the fetus has abnormalities in the process of differentiation, it may lead to its chromosomal abnormalities. In addition, if one of the spouses has a problem with the chromosomes themselves, there is a possibility that the fetus will have an abnormality. Therefore, during pregnancy, you should strictly follow the doctor’s instructions to do a good job of obstetric examination, if there is any abnormality, you need to consult a doctor in time, in order to clarify the specific causes of the disease, and give targeted treatment.