Targeted Therapy

The use of trastuzumab during pregnancy is contraindicated based on results of a systematic review of 17 studies (18 pregnancies, 19 newborns).[23] Of the fetal complications noted, occurrence of oligohydramnios/anhydramnios was the most common (61.1%) adverse event. Of the pregnancies exposed to trastuzumab during the second or third trimester, 73.3% of the pregnancies were complicated with oligohydramnios/anhydramnios. Of the pregnancies exposed to trastuzumab exclusively during the first trimester, 0% (P = .043) of the pregnancies were complicated with oligohydramnios/anhydramnios. The mean gestational age at delivery was 33.8 weeks, and the mean weight of newborns at delivery was 2,261 grams or 4.984 pounds. In 52.6% of cases, a healthy neonate was born. At the long-term evaluation, all children who were without complications at birth were healthy, with a median follow-up of 9 months, and four of nine children with complications at birth had died within an interval ranging from birth to 5.25 months. All children exposed to trastuzumab in utero exclusively in the first trimester were completely healthy at birth. The data suggest that for women who become pregnant during trastuzumab administration and wish to continue pregnancy, trastuzumab should be stopped and pregnancy would be allowed to continue.