title: Placental infections with histologically confirmed Plasmodium falciparum are associated with adverse birth outcomes in India: a cross-sectional study.
abstract: BACKGROUND
  Few studies have assessed placental malaria infections from low transmission areas by histopathology to define their impact and underlying mechanisms.
  
  
  METHODS
  Peripheral smears and rapid diagnostic tests (RDTs), placental smears and histological samples, birth weight and gestational age were collected from 2,282 deliveries in three hospitals during a one-year (2006-2007) continuous cross-sectional survey in Madhya Pradesh. Placental histopathology included all 50 cases positive by microscopy or RDT plus 456 randomly selected samples of women negative for malaria by microscopy or RDT. Histological examination included parasites, inflammatory cells, pigment in fibrin, and morphological changes.
  
  
  RESULTS
  There were 52 histology-positive cases; 38 (73.1%) active (acute and chronic) and 14 past infections. Intervillous parasitaemia was low (60% had < 1% parasitaemia) and monocytosis mostly mild (63%). Compared with uninfected placentas, acute Plasmodium falciparum infections were associated with stillbirth (RR 3.8, 95% CI 1.2-12.1), lower maternal haemoglobin (mean difference: 1.5 g/dL, 95% CI 0.5-2.5), lower birth weight (mean difference 451 g, 95% CI 169-609) and shorter gestation (mean difference 0.8 weeks, 95% CI 0.2-1.4). Chronic or past infections were not associated with these outcomes. Among the 11 peripheral Plasmodium vivax cases, placental parasites were absent, but they were associated with increased placental polymorphonuclear cells.
  
  
  CONCLUSIONS
  Malaria associated stillbirth and low birth weight in women with low protective immunity may result, at least in part, from a shortened gestation triggered by acute infection, stressing the importance of early malaria detection.
authors.forename: Rukhsana
authors.initials: R
authors.lastname: Ahmed
authors.forename: Neeru
authors.initials: N
authors.lastname: Singh
authors.forename: Feiko O
authors.initials: FO
authors.lastname: ter Kuile
authors.forename: Praveen K
authors.initials: PK
authors.lastname: Bharti
authors.forename: Pushpendra P
authors.initials: PP
authors.lastname: Singh
authors.forename: Meghna
authors.initials: M
authors.lastname: Desai
authors.forename: Venkatachalam
authors.initials: V
authors.lastname: Udhayakumar
authors.affiliation: Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK. D.J.Terlouw@liverpool.ac.uk.
authors.forename: Dianne J
authors.initials: DJ
authors.lastname: Terlouw
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007194:India / Q000453:epidemiology; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000150:complications* / Q000453:epidemiology*; D010920:Placenta / Q000469:parasitology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D011256:Pregnancy Outcome; D055815:Young Adult