title: Early umbilical cord clamping contributes to elevated blood lead levels among infants with higher lead exposure.
abstract: OBJECTIVE
  To investigate whether infant iron status, modified by umbilical cord clamping time and infant feeding mode, affected infant blood lead concentration at 6 months of age.
  
  
  METHODS
  Participants were a subset of women and their infants randomized to receive early (10 seconds) or delayed (2 minutes) umbilical cord clamping and were monitored to 6 months postpartum in Mexico City. Iron and lead status was analyzed in maternal, placental, and 6-month infant blood samples. Baseline maternal lead exposure data and infant feeding data at 2, 4, and 6 months were collected.
  
  
  RESULTS
  In the total sample, maternal blood lead concentration, infant ferritin, and breast-feeding practices predicted infant blood lead concentration. Among infants with higher placental blood lead concentration and breast-fed infants not receiving any iron-fortified formula or milk at 6 months, early clamping increased infant blood lead concentration, an effect mediated in part via decreased infant iron status.
  
  
  CONCLUSIONS
  Early cord clamping, by decreasing infant iron status, contributes to higher blood lead concentrations at 6 months of age among infants at high risk.
authors.affiliation: Department of Nutrition, Program in International and Community Nutrition, University of California, Davis, California 95616-8669, USA.
authors.forename: Camila M
authors.initials: CM
authors.lastname: Chaparro
authors.forename: Raymond
authors.initials: R
authors.lastname: Fornes
authors.forename: Lynnette M
authors.initials: LM
authors.lastname: Neufeld
authors.forename: Gilberto
authors.initials: G
authors.lastname: Tena Alavez
authors.forename: Raúl
authors.initials: R
authors.lastname: Eguía-Líz Cedillo
authors.forename: Kathryn G
authors.initials: KG
authors.lastname: Dewey
mesh_terms: D001942:Breast Feeding; D002516:Ceramics / Q000737:chemistry; D003250:Constriction; D004781:Environmental Exposure; D005260:Female; D005293:Ferritins / Q000097:blood; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D008297:Male; D008423:Maternal Age; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000098:blood supply / Q000737:chemistry; D011247:Pregnancy; D012044:Regression Analysis; D013997:Time Factors; D014470:Umbilical Cord
chemical_list: D007854:Lead; D005293:Ferritins