LAUSR

Key Points Question Is gestational age at initiation of chemotherapy during pregnancy associated with risk of congenital malformations? Findings In this cohort study including 755 pregnant women with cancer, the risk of major congenital malformations was elevated when first chemotherapy exposure was prior to 12 weeks of gestation, whereas the occurrence of major congenital malformations was similar to expected rates in the general population when chemotherapy was initiated after 12 weeks of gestation. Meaning The findings of this study could allow clinicians to better tailor chemotherapy during pregnancy and to inform patients on fetal risks of malformations.