Comparison of the effectiveness of two-dose versus three-dose sulphadoxine-pyrimethamine in preventing adverse pregnancy outcomes in Nigeria

Background & objectives: Three doses of intermittent preventive treatment with sulphadoxine-pyrimethamine (IPTp-SP) has been adopted as the new recommendation for prevention of malaria in pregnancy. This study evaluated the effectiveness of two-dose versus three-dose of SP for IPTp-SP in the prevention of low birth weight (LBW) and malaria parasitaemia. Methods: An open, randomized, controlled, longitudinal trial was conducted in a secondary level hospital in Nsukka region of Enugu State, Nigeria. A sample of 210 pregnant women within gestational ages of 16–24 wk were recruited at antenatal clinics and equally randomized to either a two-dose SP or three-dose SP group. The primary endpoints were LBWs, peripheral, and placental parasitaemia, while the secondary endpoints were maternal anaemia, pre-term birth, clinical malaria and adverse effects of SP. Results: Among 207 cases followed till delivery, the prevalence of parasitaemia was lower in three-dose group than in two-dose group for both peripheral (9.3% versus 27.8%) and placental (10.6% versus 25.6%) parasitaemia. The adjusted odds ratios (aOR) were 0.15 [95% confidence interval (CI), 0.05 – 0.45] and 0.17 (95% CI, 0.06–0.51), respectively. The prevalence of LBW was also lower in three-dose (3.5%) than in two-dose (12.2%) group (aOR, 0.15; 95% CI, 0.04–0.63); however, the prevalence of maternal anaemia, pre-term births, clinical malaria and SP adverse effects were similar between the two arms of treatment. Interpretation & conclusion: Addition of a third SP dose to the standard two-dose SP for IPTp led to improved reductions in the risk of some adverse pregnancy outcomes