THE EFFICACY OF ANTIMALARIAL REGIMENS CONTAINING SULFADOXINE-PYRIMETHAMINE AND OR CHLOROQUINE IN PREVENTING PERIPHERAL AND PLACENTAL PLASMODIUM-FALCIPARUM INFECTION AMONG PREGNANT-WOMEN IN MALAWI/

To define an effective and deliverable antimalarial regimen for use du ring pregnancy, pregnant women at highest risk of malaria (those in th eir first or second preg nancy) in an area of Malawi with high transmi ssion of chloroquine (CQ)-resistant Plasmodium falciparum were placed on CQ and/or sulfadoxine-pyrimethamine (SP). Of 38 pregnant women who received CQ treatment followed by weekly CQ prophylaxis (CQ/CQ) for at least 45 days prior to delivery, 32% had placental malaria infection, compared with 26% of 50 pregnant women who received a treatment dose of SP followed by weekly CQ prophylaxis (SP/CQ), and only 9% of 71 pre gnant women who received a two-dose SP regimen (SP/SP; given once duri ng the second trimester and repeated at the beginning of the third tri mester) (P = 0.006, by chi-square test). During the peak transmission season from April to July, 47% of the women who received CQ/CQ had pla cental malaria infection at delivery, as compared with 37% of the wome n who received SP/CQ, and 10% of women who received SP/SP (P = 0.004, by chi-square test). Among women in their first or second pregnancy, t wo treatment doses of SP were highly effective in decreasing the propo rtion of women with placental malaria infection at delivery.