title: Very low maternal lead level in pregnancy and birth outcomes in an eastern Massachusetts population.
abstract: OBJECTIVE
  Maternal lead exposure is associated with poor birth outcomes in populations with moderate to high blood levels. However, no studies have looked at exposure levels commonly experienced by US women.
  
  
  METHODS
  We evaluated the relationship between maternal red blood cell (RBC) lead levels in midpregnancy and birth outcomes in 949 mother-child pairs in a prebirth cohort. We used multiple linear regression and logistic regression, adjusted for potential confounders including maternal age, race, prepregnancy body mass index, and smoking to relate maternal lead to infant birth size and risk for preterm birth (<37 weeks).
  
  
  RESULTS
  Mean RBC lead level was 1.2 μg/dL (range, 0.0-5.0). Mean (standard deviation) birthweight was 3505 (520) g, birthweight for gestational age z-score 0.22 (0.93), and length of gestation 39.5 (1.7) weeks. Mothers in the highest versus lowest lead quartile did not have higher odds (OR, 1.85; 95% confidence interval [CI], 0.79-4.34) of preterm delivery; after stratifying by child sex, there was an association among males (OR, 5.51; 95% CI, 1.21-25.15) but not females (OR, 0.82; 95% CI, 0.24-2.85). Maternal RBC lead was not associated with any continuous outcomes in combined or sex-stratified analyses.
  
  
  CONCLUSIONS
  Maternal lead exposure, even at very low levels, may adversely affect some childbirth outcomes, particularly preterm birth among males.
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA.
authors.forename: Meghan
authors.initials: M
authors.lastname: Perkins
authors.affiliation: Departments of Preventive Medicine and Pediatrics, Icahn School of Medicine at Mt. Sinai, New York, NY.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Wright
authors.affiliation: Channing Laboratory, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA.
authors.forename: Chitra J
authors.initials: CJ
authors.lastname: Amarasiriwardena
authors.affiliation: Channing Laboratory, Brigham and Women׳s Hospital and Harvard Medical School, Boston, MA.
authors.forename: Innocent
authors.initials: I
authors.lastname: Jayawardene
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Rifas-Shiman
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA. Electronic address: Emily_Oken@hphc.org.
authors.forename: Emily
authors.initials: E
authors.lastname: Oken
mesh_terms: D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007854:Lead / Q000097:blood* / Q000633:toxicity; D007855:Lead Poisoning / Q000150:complications / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008423:Maternal Age; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D009035:Mothers; D011247:Pregnancy; D011248:Pregnancy Complications / Q000139:chemically induced / Q000453:epidemiology*; D047928:Premature Birth / Q000139:chemically induced / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D007854:Lead
keywords: Birthweight; Lead; Pregnancy; Preterm birth