Abstract Background Sulfadoxine-pyrimethamine (SP) is used as intermittent preventive therapy in pregnancy (IPTp) for malaria in sub-Saharan Africa. The resistance marker dhps A581G has been associated with reduced IPTp-SP efficacy and enhanced morbidity in SP recipients. Methods We measured SP-resistance allele frequencies in Malawian women participating in a trial comparing IPTp with SP against intermittent screening by rapid diagnostic tests (ISTp). We genotyped polymerase chain reaction-detected parasites using deep sequencing of SP-resistance alleles. Results Among 125 placental infections, A581G-bearing parasites were associated with reduced birth weight (mean difference [MD], 252 g; 95% confidence interval [CI], 46–457; P = .017). Relative to ISTp, IPTp-SP was associated with higher birth weights in women with wild-type parasites (MD, 116 g; 95% CI, −40 to 272; P = .142) and lower birth weights in women with A581G-bearing parasites (MD, 192 g; 95% CI, −264 to 648; P = .385) ( P interaction = .033). Similar associations were noted on gestational age ( P interaction = .075). Amongst only IPTp-SP recipients, relative to women who last received SP > 4 weeks before delivery, recent SP receipt was associated with lower birth weight in women with wild-type parasites (MD, 118 g; 95% CI, −376 to 139; P = .361) and higher birth weight in women with A581G-bearing parasites (MD, 783 g; 95% CI, −20 to 1586; P = .054) ( P interaction = .005). Conclusions The effectiveness in birth weight of IPTp-SP is compromised by A581G-bearing parasites, but there was no evidence that the adverse effects of these parasites are exacerbated by antenatal SP. ISRCTN Registry www.isrctn.com/ISRCTN69800930 . In Malawian pregnant women with placental malaria, the presence of parasites with the SP-resistance allele dhps A581G was associated with lower birth weights, but antenatal SP receipt did not exacerbate the adverse consequences of malaria in pregnancy.
【저자키워드】 prevention, malaria, drug resistance, Malaria in pregnancy, placental malaria,