Genetic mutations during pregnancy may be related to chromosomal abnormalities, viral infections, radiation and other causes. 1. Chromosomal abnormality: if both husband and wife have some kind of chromosomal disease, it may affect the growth of the fetus, thus the genetic mutation occurs. 2. Viral infection: Because the immunity of pregnant women is relatively low after pregnancy, they are easy to be infected by viruses, and if the fetus is repeatedly stimulated by viruses, genetic mutation may occur. 3. Radiation: If the pregnant woman is often exposed to radioactive substances after pregnancy, she may be exposed to radiation, which will lead to harmful substances entering the pregnant woman’s body, affecting the growth of the fetus and the occurrence of genetic mutation. It can be seen that pregnant women should do a good job of prenatal checkups, regular maternity checkups, strengthen immunity during pregnancy and avoid exposure to radioactive substances.