Infants exposed in utero to chemotherapy have more adverse events than those whose mothers delay treatment until after delivery, but such complications are not clinically important, researchers conclude in the Lancet Oncology.

The study included 400 women diagnosed with early breast cancer during pregnancy, about half of whom received chemotherapy. None received chemotherapy in the first trimester.

Chemotherapy was associated with lower birth weight and an increase in obstetric complications (17% of treated women vs. 9% of the untreated) and neonatal events (31 vs. 7 events). However, the researchers say these outcomes were “not clinically significant” and were “most likely related to premature delivery.” Birth defects, Apgar scores, and blood disorders did not differ between the groups.

The authors conclude that if their results “are substantiated by other studies, breast cancer during pregnancy could be treated as it is in non-pregnant women without putting fetal and maternal outcome at substantially increased risk.”

Source:Lancet Oncology