Pregnancy outcome following gestational exposure to montelukast: A prospective cotrolled study

Abstract

Background Asthma is the most common respiratory crisis complicating pregnancy. Montelukast is prescribed orally for chronic treatment of asthma. Although animal reproductive studies show no evidence of teratogenic effects, there are no human studies assessing possible effects on the developing fetus with in utero exposure. Despite known risks associated with poorly controlled asthma, lack of safety data prevents women from using montelukast in pregnancy. Our aim is to evaluate pregnancy outcomes following gestational exposure to montelukast. Methods This prospective controlled study enrolls pregnant women who contact Motherisk about exposure to montelukast. These women are followed up using standardized data collection forms. Montelukast-exposed women are compared to a disease-matched group using inhalers for similar indications and a group of women exposed to known non-teratogens. Rates of major anomalies and other adverse outcomes are compared between groups. Results To date, 64 women exposed to montelukast during 1st trimester have been enrolled, of which 24 have used it throughout pregnancy. Outcomes of this group include: 62 (96.9%) live births, 2 (3.1%) SA and 2 (3.1%) major malformations. Upon comparison to controls, no statistical differences are apparent in these or any other endpoints of interest. Conclusions Data collected thus far in this ongoing study appear to suggest no increased risk for major malformations above baseline of 1–3%, following use of montelukast in pregnancy. Clinical Pharmacology & Therapeutics (2005) 77, P30–P30; doi: 10.1016/j.clpt.2004.12.005