Patient's question:
NoDoctor's answer:
During the first three months of pregnancy, medication can easily cause malformations because the fertilized egg is in the stage of successive differentiation and fusion, and the various systems have not yet fully formed, making them susceptible to drug effects. After the fourth month of pregnancy, the fetal organs have already formed, and drugs no longer have teratogenic effects. Except for thalidomide, the following drugs have or may have teratogenic effects, so they should be avoided or used with caution during the first three months.(1) Anticancer drugs such as methotrexate can easily cause miscarriage and malformations like anencephaly, hydrocephalus, and cleft palate. The risk is even greater when combined with other anticancer drugs. Other drugs, including busulfan, chlorambucil, 6-mercaptopurine, cyclophosphamide, demethylcolchicine, mithramycin, vincristine, uracil, and iodine therapy or pelvic radiation, can also cause fetal malformations.