A total of 1320 consenting women who present at a rural antenatal clinic after 14 but before 26 completed gestation weeks will be enrolled. One third of the women will receive antenatal care according to national recommendations, including regular visits to health centre, screening for pregnancy complications, haematinic and vitamin A supplementation and two doses of presumptive malaria treatment with sulfadoxine-pyrimethamine. Another third will receive otherwise the same care, but sulfadoxine-pyrimethamine treatment is given at monthly intervals. The final third receives standard antenatal care, sulfadoxine-pyrimethamine treatment at monthly intervals and two doses of presumptive STI treatment with azithromycin. Women are monitored throughout pregnancy and delivery and newborn growth will be followed up for five years.