The effects of mefloquine treatment in pregnancy

We investigated the relationship between mefloquine antimalarial treatment and the outcome of pregnancy in Karen women living in an area along the wes tern border of Thailand where multidrug-resistant Plasmodium falciparum inf ections are common. Of 3,587 pregnancies investigated, 208 (5.8%,) were exp osed to mefloquine, 656(18.3%) to quinine only, and 909(25.3%) to other ant imalarials, and 2,470 (68.9%) had no documented malaria. There were 61 stil lbirths and 313 abortions. Nomen who received mefloquine treatment during b ut net before pregnancy had a significantly greater risk of stillbirth than did women treated with quinine alone (odds ratio [OR]. 4.72; 95% confidenc e interval [CI], 1.7-12.7), women exposed to other treatments (OR, 5.10; 95 % CI, 2-13.1),and women who had no malaria (OR, 3.50; 95% CI, 1.6-7.6) (P < .01). This association remained after adjustment for all identified confoun ding factors. Mefloquine was not associated with abortion, low birth weight , neurological retardation, or congenital malformations. Mefloquine treatme nt during pregnancy was associated with an increased risk of stillbirth.