Fetal safety of loratadine use in the first trimester of pregnancy:: A multicenter study

Background: Women in their childbearing years often require drug therapy for allergic conditions. Loratadine, a newer nonsedating antihistamine, is often used because of its preferred side effect profile. To date no published data exist on the safety of loratadine use in pregnancy. Objective: We sought to determine whether the use of loratadine in the first trimester of pregnancy was associated with an increased risk for major malformations. Secondary outcomes included rates of miscarriage, birth weights, and gestational age at delivery. Methods: All women were prospectively enrolled from 4 participating centers. Detailed maternal medical history and drug exposures were collected at intake, whereas pregnancy complications and outcomes were collected at follow-up. A group of unexposed control subjects were recruited and followed up in a similar manner. Results: This report includes follow-up on 161 loratadine exposed pregnancies and an equal number of unexposed control subjects. Maternal characteristics (age, pregnancy history, alcohol consumption, and smoking habits) were not different between the 2 groups. There were 5 malformations observed in the exposed group and 6 in the control group, which was not significantly different (P = .9) Similarly, the live birth rate, gestational age at delivery, and birth weights were not different between the 2 groups. Conclusion: These results suggest that loratadine use in pregnancy is not associated with a large risk for major malformations. Further studies are warranted to confirm these findings and to increase study power. (J Allergy Clin Immunol 2003;111:479-83.).