Results from the ongoing prospective, observational EXPECT study indicate small percentages of negative birth outcomes among women who received Xolair 8 weeks before conception or during pregnancy.

Researchers assessed pregnancy outcomes among 186 women exposed to Xolair (omalizumab, Genentech) within 8 weeks before conception or during pregnancy. Data were collected at study enrollment, each trimester of pregnancy, delivery and up to 18 months after delivery. There were 174 live births of 178 infants during the study period. All women received omalizumab during the first trimester of pregnancy.

Sixty-four percent of mothers had severe asthma, 33.5% had moderate asthma, and 2.4% had mild asthma.

Overall, 15.2% of infants had confirmed congenital anomalies, and 6.2% had a major birth defect. Fourteen percent of infants were premature, and of these, 12.5% were considered small for gestational age.