4. At 6 weeks post-partum, if a woman has peripheral parasitaemia she will be treated with SP and followed up for parasite clearance on days 14 and 28 post-treatment. If there is no parasite clearance on day 14 and/or day 28 a course of rescue medication (quinine) will be given. This part of the study is necessary to assess the efficacy of SP to clear parasitaemia.