A retrospective review of 227 consecutive breast cancer patients who were 35 years of age or younger and who had been given doxorubicin-containing adjuvant chemotherapy was conducted to determine the frequency of pregnancy and its effect on the clinical course of the disease. Also, the status of the newborn was evaluated. There were 33 pregnancies in 25 patients (10 pregnancies were terminated, 2 patients had spontaneous abortions, and 19 patients gave birth to full-term offspring without fetal malformation). Two patients were still pregnant at the time of this report. The median interval between the completion of chemotherapy and pregnancy was 12 months. Eight patients who became pregnant experienced temporary amenorrhea during chemotherapy. Of the 25 patients who became pregnant, recurrent disease subsequently developed in 7 and 3 died. A patient's disease-free and overall survival status was not adversely effected by pregnancy. These data illustrate that in a sizeable fraction of patients 35 years of age or younger treated with adjuvant doxorubicin-containing therapy, ovarian function remained intact and subsequent pregnancy did not affect the disease-free or overall survival of the patients.