Prospective controlled study of hydroxyzine and cetirizine in pregnancy.

BACKGROUND: Hydroxyzine has been used for many years for the treatment of allergic symptoms. Cetirizine, an active metabolite of hydroxyzine, has become very popular for the treatment of allergy symptoms because of its efficacy without the sedating effects of the parent compound. Little is known about the safety of hydroxyzine use during pregnancy, and there are no published reports on the effects of cetirizine on pregnancy outcome.

OBJECTIVE: To determine whether hydroxyzine and cetirizine are associated with any increased risk of malformations in humans.

METHODS: All pregnant women counseled by the Motherisk Program in Toronto on the use of hydroxyzine or cetirizine during their pregnancies were enrolled in a prospective, controlled, observational study. The control group consisted of pregnant women matched for age, smoking, and alcohol consumption who were counseled for non-teratogenic drug.

RESULTS: One hundred twenty women were followed after exposure to either hydroxyzine or cetirizine during pregnancy. Of these, 53 were exposed to hydroxyzine during organogenesis and 39 to cetirizine. There were no significant differences found between the hydroxyzine or cetirizine groups and the control groups in the pregnancy outcome: rate of livebirths, spontaneous or therapeutic abortion, or stillbirth. There was also no difference in the rates of major or minor anomalies, mean birth weight, mode of delivery, gestational age, or presence of neonatal distress.

CONCLUSIONS: The use of hydroxyzine and cetirizine does not appear to be associated with increased teratogenic risk.