20 Dosing regimens of sulfadoxine-pyrimethamine for malaria prophylaxis and risk of low birth weight among HIV positive women in Lusaka, Zambia M. C. Smid, B. Vwalika, M. Stoner, S. Dotters-Katz, A. Kumwenda, E. Stringer, J. S. A. Stinger Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina e Chapel Hill, Department of Obstetrics and Gynecology, University of Zambia, Lusaka, Zambia, Department of Epidemiology, University of North Carolina e Chapel Hill, Division of Global Women’s Health, Department of Obstetrics and Gynecology, University of North Carolina e Chapel Hill OBJECTIVES: To evaluate the effect of number of doses of sulfadoxine-pyrimethamine (SP), the standard preventative therapy recommended for pregnant women in high malaria risk regions, and the risk of low birth weight (LBW) (< 2500 g) among HIV positive women in an urban African population. METHODS: The Zambia Electronic Perinatal Record System (ZEPRS) was used to review pregnancy outcomes of HIV positive women between February 2006 and December 2012 in Lusaka, Zambia. Maternal characteristics and infant birth weights were compared with number of doses of SP received during antenatal care. A log binomial model was used estimate the risk ratio of LBW by number of SP doses received among HIV positive women. RESULTS: The cohort of 44,707 HIV positive women included 10, 901 (25%) who received no doses of SP, 21,396 (48%) who received one dose, 8113 (18%) who received two doses, and 4914 (11%) who received all three recommended doses of SP. Of the 45, 513 infants in our cohort, 3.5% (n1⁄41612) were twins. Among HIV positive women, multiple gestation (adjusted risk ratio (ARR) 5.1, confidence interval (CI) 4.7-5.6) hypertension (ARR 1.6; CI 1.4-1.7), body mass index <20 kg/m2 (ARR 1.4, CI 1.2-1.5), CD4 count at first antenatal visit < 200 (ARR 1.3, CI, 1.2-1.5), hemoglobin < 8 mg/dL (ARR 1.3; CI 1.2-1.5) and highly active anti-retroviral therapy (ARR 1.1, CI 1.1-1.2) were associated with higher risk of LBW. In the multivariable analysis, number of doses of SP and risk of LBW among HIV positive women was not statistically significant, although there was a trend towards significance with increasing number of SP doses inversely correlated with risk of LBW (three SP doses: ARR 0.8, CI 0.7-1.0; two SP doses ARR 0.9, CI 0.8-1.1; one SP dose ARR 1.0, CI 0.9-1.1 compared to no SP doses). CONCLUSIONS: The majority of HIV positive women in our cohort did not receive the World Health Organization’s recommended three doses of malaria SP prophylaxis. Those who received no doses may have received co-trimoxazole as HIV infection prophylaxis, which is not accurately recorded in ZEPRS. However those receiving any dose of SP should not have been on co-trimoxazole as co-administration is contra-indicated due to unknown toxicity profile. Improving awareness and access to the recommended malaria prophylaxis particularly among HIV positive pregnant women not receiving cotrimoxazole is key to reducing LBW in low resource countries with high HIV and malaria disease burdens. LEARNING OBJECTIVE: 1) Learners will be able to identify the recommended number of doses of SP for malaria prophylaxis in HIV positive pregnant women. 2) Learners will be able to identify risk