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Chemotherapeutic agents

It is rare for cancer and pregnancy to coincide, occurring in only 1 in 1,000 pregnancies and making up less than 0.1% of all recorded malignant tumors. However, when this does occur, there are many complications and great, although not well understood, risks to the fetus in the event that chemotherapy drugs are used. The majority of these drugs are cytotoxic, meaning that they have the potential to be carcinogenic, mutagenic, and teratogenic. If used during the first two weeks of pregnancy, they may inhibit implantation of the fetus and led to miscarriage. They may particularly act as teratogenic agents if used from the second to eighth week, as this is a critical stage for tissue differentiation. The highest risk continues through the first trimester, making up 14% of major malformations. Chemotherapeutic drugs are considered safer to use during the second and third trimester, but there is limited research to fully support this.