title: Evaluation of sulphadoxine-pyrimethamine for intermittent preventive treatment of malaria in pregnancy: a retrospective birth outcomes study in Mansa, Zambia.
abstract: BACKGROUND
  Intermittent preventive treatment of malaria in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) decreases placental parasitaemia, thus improving birth outcomes. Zambian policy recommends monthly SP-IPTp doses given presumptively during pregnancy at each antenatal examination, spaced one month apart after 16 weeks of gestation. The effectiveness of SP-IPTp was evaluated in Zambia where a recent study showed moderate prevalence of Plasmodium falciparum parasites with genetic mutations that confer SP resistance.
  
  
  METHODS
  HIV-negative women were enrolled at the time of delivery at two facilities in Mansa, Zambia, an area of high malaria transmission. Women were interviewed and SP exposure was determined by antenatal card documentation or self-reports. Using Poisson regression modelling, the effectiveness of SP-IPTp was evaluated for outcomes of parasitaemia (microscopic examination of maternal peripheral, cord, and placental blood films), maternal anaemia (Hb < 11 g/dl), placental infection (histopathology), and infant outcomes (low birth weight (LBW), preterm delivery, and small for gestational age) in women who took 0-4 doses of SP-IPTp.
  
  
  RESULTS
  Participants included 435 women, with a median age of 23 years (range 16-44). Thirty-four women took zero doses of SP-IPTp, while 115, 142 and 144 women took one, two, or ≥ three doses, respectively. Multivariate Poisson regression models considering age, mosquito net usage, indoor residual spraying, urban home, gravidity, facility, wet season delivery, and marital status showed that among paucigravid women ≥ two doses of SP-ITPp compared to one or less doses was associated with a protective effect on LBW (prevalence ratio (PR) 0.33, 95% confidence interval (CI) 0.12-0.91) and any infection (PR 0.76, CI 0.58-0.99). Multivariate models considering SP-IPTp as a continuous variable showed a protective dose-response association with LBW (paucigravid women: PR 0.54, CI 0.33-0.90, multigravid women: PR 0.63, CI 0.41-0.97).
  
  
  CONCLUSIONS
  In Mansa, Zambia, an area of moderate SP resistance, ≥ two doses of SP-IPTp were associated with a protective effect from malaria in pregnancy, especially among paucigravid women. Each dose of SP-IPTp contributed to a 46 and 37% decrease in the frequency of LBW among paucigravid and multigravid women, respectively. SP-IPTp remains a viable strategy in this context.
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. kmace@cdc.gov.
authors.forename: Kimberly E
authors.initials: KE
authors.lastname: Mace
authors.affiliation: School of Medicine, Department of Public Health, University of Zambia, Lusaka, Zambia. victorchalwe2011@yahoo.com.
authors.forename: Victor
authors.initials: V
authors.lastname: Chalwe
authors.affiliation: United States Peace Corps, Lusaka, Zambia. bkatalen@tulane.edu.
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Katalenich
authors.affiliation: Tropical Diseases Research Centre, Ndola, Zambia. michaelnambozi@yahoo.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Nambozi
authors.affiliation: Ndola Central Hospital, Ndola, Zambia. dmubikayi@yahoo.com.
authors.forename: Luamba
authors.initials: L
authors.lastname: Mubikayi
authors.affiliation: Wusakile Mine Hospital, Kitwe, Zambia. chikuli.mulele@mopani.com.zm.
authors.forename: Chikuli K
authors.initials: CK
authors.lastname: Mulele
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. rwiegand@cdc.gov.
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Wiegand
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. Scott.Filler@theglobalfund.org.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Filler
authors.affiliation: National Malaria Control Centre, Lusaka, Zambia. mkamuliwo@yahoo.co.uk.
authors.forename: Mulakwa
authors.initials: M
authors.lastname: Kamuliwo
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. acraig@cdc.gov.
authors.forename: Allen S
authors.initials: AS
authors.lastname: Craig
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. ktan@cdc.gov.
authors.forename: Kathrine R
authors.initials: KR
authors.lastname: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000627:therapeutic use*; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control*; D015999:Multivariate Analysis; D016012:Poisson Distribution; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000517:prevention & control*; D015995:Prevalence; D011739:Pyrimethamine / Q000627:therapeutic use*; D012189:Retrospective Studies; D013413:Sulfadoxine / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult; D015024:Zambia / Q000453:epidemiology
chemical_list: D000962:Antimalarials; D004338:Drug Combinations; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D011739:Pyrimethamine