Effectiveness of intermittent preventive treatment with sulphadoxine-pyrimethamine for control of malaria in pregnancy in western Kenya: a hospital-based study

Abstract

Objective: To monitor the effectiveness of intermittent preventive treatment (IPT) with sulphadoxine-pyrimethamine (SP) for the control of malaria in pregnancy at delivery in the Provincial Hospital in Kisumu, Kenya, and to assess the effect of IPT in participants in a cohort study.

Methods: Between June 1999 and June 2000, information on IPT and birth outcome was collected in 2302 consecutive deliveries. A group of 889 women, who were enrolled in a cohort to assess the interaction between malaria and HIV, were analysed separately because of the enrollment criteria and different access to health care.

Results: The prevalence of placental malaria was 13.8% and of low birthweight (LBW) was 12.2%. In multivariable analysis, IPT (> or =1 dose of SP) was associated with a reduction in placental malaria and LBW [adjusted odds ratio (OR) 0.56, 95% confidence interval (CI) 0.39-0.83 and OR 0.65, 95% CI 0.45-0.95, respectively]. An adjusted mean increase in birthweight of 61 g was seen (95% CI 22-101 g) for each increment in number of SP doses (> or =2 doses grouped together). IPT was associated with a reduction in placental malaria in HIV-seronegative women (OR 0.49, 95% CI 0.28-0.86) but this was not significant among HIV-seropositive women (OR 0.45, 95% CI 0.20-1.05). A significant effect on birthweight could not be detected among participants in the HIV-cohort.

Conclusions: This evaluation confirms that IPT with SP is effective in reducing placental malaria and LBW. It will be important to increase coverage of IPT and to extend IPT to antenatal clinics in peri-urban and rural areas.