Evaluation of Alternative Antimalarial Drugs for Malaria in Pregnancy

Inclusion Criteria: Trial 1: * Permanent resident in the area * Gestational age at the first antenatal visit ≤ 28 weeks * Signed informed consent * Agreement to deliver in the study site's maternity(ies) wards Trial 2: * Permanent resident in the area. * Gestational age at the first antenatal visit ≤ 28 weeks * HIV seropositive (after voluntary counseling and testing) * Indication to receive CTX prophylaxis (according to the national guidelines) * Signed informed consent * Agreement to deliver in the study site's maternity(ies) wards. Exclusion Criteria: Trial 1: * Residence outside the study area or planning to move out in the following 18 months from enrollment * Gestational age at the first antenatal visit \> 28 weeks of pregnancy * Known history of allergy to sulfa drugs or mefloquine * Known history of severe renal, hepatic, psychiatric or neurological disease * MQ or halofantrine treatment in the preceding 4 weeks * HIV infection * Participating in other studies Trial 2: * Residence outside the study area or planning to move out in the following 10 months from enrollment * Gestational age at the first antenatal visit \> 28 weeks of pregnancy * Known history of allergy to CTX or MQ * Known history of severe renal, hepatic, psychiatric or neurological disease * MQ or halofantrine treatment in the preceding 4 weeks