Motherisk update: Cancer chemotherapy during pregnancy

Question: I have an 8-weeks' pregnant patient who was diagnosed with stage III Hodgkin's disease last week. The oncologist suggests delaying chemotherapy until the second trimester. What are the effects of chemotherapy on a fetus after the first trimester? Where can I find reliable information on the subject? Answer: Available data suggest that exposure to chemotherapy during the first trimester of pregnancy is associated with increased risk of major malformations. Exposure during the second and third trimesters does not result in major malformations, but could have nonteratogenic effects, such as low birth weight. The brain develops throughout pregnancy, and it could be affected later in pregnancy.