Case-control study of fetal and newborn outcomes after anti-HER2 therapy during pregnancy

Targeted therapies directed against HER2 are the cornerstone of medical treatment for HER2-positive breast cancers. During pregnancy, the benefits of treatment to the mother must be weighed against the potential harm to the fetus. A case-control study within the WHO international pharmacovigilance database VigiBase investigated 3558 reports mentioning exposure to anticancer agents during pregnancy. Exposure to anti-HER2 agents (n=328) during pregancy was significantly associated with an overreporting of oligohydramnios, congenital respiratory tract disorders, and neonatal kidney failure relative to other anticancer drugs (n=3230). The authors conclude that anti-HER2 agents are associated with severe adverse fatal or newborn outcomes and should be contraindicated during pregancy.