title: Maternal blood and hair manganese concentrations, fetal growth, and length of gestation in the ISA cohort in Costa Rica.
abstract: BACKGROUND
  Animal studies have shown that both deficiency and excess manganese (Mn) may result in decreased fetal size and weight, but human studies have reported inconsistent results.
  
  
  METHODS
  We examined the association of blood and hair Mn concentrations measured at different times during pregnancy with fetal growth among term births and length of gestation in a cohort of 380 mother-infant pairs living near banana plantations aerially sprayed with Mn-containing fungicides in Costa Rica. We used linear regression and generalized additive models to test for linear and nonlinear associations
  
  
  RESULTS
  Mean (± SD) blood Mn concentration was 24.4 ± 6.6 μg/L and geometric mean (geometric SD) hair Mn concentration was 1.8 (3.2) μg/g. Hair Mn concentrations during the second and third trimesters of gestation were positively related to infant chest circumference (β for 10-fold increase = 0.62 cm; 95% CI: 0.16, 1.08; and β = 0.55 cm; 95% CI: -0.16, 1.26, respectively). Similarly, average maternal hair Mn concentrations during pregnancy were associated with increased chest circumference (β for 10-fold increase = 1.19 cm; 95% CI: 0.43, 1.95) in infants whose mothers did not have gestational anemia, but not in infants of mothers who had gestational anemia (β = 0.39 cm; 95% CI: -0.32, 1.10; pINT=0.14). All these associations were linear. Blood Mn concentrations did not show consistent linear nor nonlinear relationships with any of the birth outcomes
  
  
  CONCLUSIONS
  Mn plays an important role in fetal development, but the extent to which environmental exposures may cause adverse health effects to the developing fetus is not well understood. Among women living near banana plantations in Costa Rica, we did not observe linear or nonlinear associations of Mn concentrations with lowered birth weight or head circumference, as reported in previous studies. However, we did find positive linear associations between maternal hair Mn concentrations during pregnancy and infant chest circumference.
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, P.O. Box 86-3000 Heredia, Costa Rica; Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, 1995 University Ave, Suite 265, Berkeley, CA 94704, USA. Electronic address: ana.mora.mora@una.cr.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Mora
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, P.O. Box 86-3000 Heredia, Costa Rica. Electronic address: berendina.vanwendel.dejoode@una.cr.
authors.forename: Berna
authors.initials: B
authors.lastname: van Wendel de Joode
authors.affiliation: Centre de Recherche Interdisciplinaire sur la Biologie, la Santé, la Société et l' Environnement (CINBIOSE), Université du Québec à Montréal, Pavillon des sciences, 141, Avenue du Président Kennedy, H2× 1Y4 Montréal, Québec, Canada. Electronic address: mergler.donna@uqam.ca.
authors.forename: Donna
authors.initials: D
authors.lastname: Mergler
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, P.O. Box 86-3000 Heredia, Costa Rica. Electronic address: leonel.cordoba.gamboa@una.cr.
authors.forename: Leonel
authors.initials: L
authors.lastname: Córdoba
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, P.O. Box 86-3000 Heredia, Costa Rica. Electronic address: jucanoc@gmail.com.
authors.forename: Camilo
authors.initials: C
authors.lastname: Cano
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, P.O. Box 86-3000 Heredia, Costa Rica. Electronic address: maria.quesada.varela@una.cr.
authors.forename: Rosario
authors.initials: R
authors.lastname: Quesada
authors.affiliation: Microbiology and Environmental Toxicology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA. Electronic address: drsmith@ucsc.edu.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Smith
authors.affiliation: Laboratory of Toxicology, College of Pharmacy, Federal University of Bahia, Av. Barão de Jeremoabo s/n Campus Universitário de Ondina, 40170-115 Salvador, Bahia, Brazil. Electronic address: antomen@ufba.br.
authors.forename: José A
authors.initials: JA
authors.lastname: Menezes-Filho
authors.affiliation: Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, 1995 University Ave, Suite 265, Berkeley, CA 94704, USA. Electronic address: eskenazi@berkeley.edu.
authors.forename: Brenda
authors.initials: B
authors.lastname: Eskenazi
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D047109:Fetal Development; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008345:Manganese / Q000032:analysis* / Q000097:blood; D011247:Pregnancy; D055815:Young Adult
chemical_list: D008345:Manganese
keywords: Birth outcomes; Birth weight; Costa Rica; Manganese; Pesticides; Pregnancy