Pregnancy and Fetal Outcomes After Exposure to Mefloquine in the Pre- and Periconception Period and During Pregnancy

BACKGROUND Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. METHODS The effect of exposure to mefloquine on pregnancy and offspring outcomes was evaluated using the F. Hoffmann-La Roche global drug safety database for the time frame 31 January 1986 through 26 October 2010. We investigated pregnancy and fetal outcomes in maternal, paternal, and both-parent exposure cases with a focus on congenital malformations and fetal loss. The main outcome measures were birth defect prevalence and types of malformations. RESULTS A total of 2506 cases of mefloquine exposure during pregnancy or in the pre- and periconception period were evaluated. Most cases were maternal prospective (outcome of the pregnancy unknown at the time of reporting; n = 2246 [89.6%]) followed by maternal retrospective cases (outcome of the pregnancy known at the time of reporting; n = 227 [9.0%]), with small numbers of paternal and both-parent exposure cases. Of the total 2246 mefloquine maternal prospective exposures (95.2%), 2139 occurred before conception and/or during the first trimester. Of 1383 maternal prospective cases with known outcome, 978 (70.7%) resulted in delivery, 405 (29.3%) resulted in abortion (112 spontaneous, 293 therapeutic), and 43 resulted in birth defects, corresponding to a birth defect prevalence of 4.39% (43 of 978). Prospective cases overall showed no specific pattern of birth malformations. CONCLUSIONS The drug safety database analysis of mefloquine exposure in pregnancy showed that the birth defect prevalence and fetal loss in maternal, prospectively monitored cases were comparable to background rates.