title: Blood lead at currently acceptable levels may cause preterm labour.
abstract: OBJECTIVE
  Although occupational and environmental exposures to lead have been dramatically reduced in recent decades, adverse pregnancy outcomes have been observed at 'acceptable' levels of blood lead concentrations (≤ 10 μg/dl).
  
  
  METHODS
  Blood samples were collected from 348 singleton pregnant women, aged 16-35 years, during the first trimester of pregnancy (8-12 weeks) for lead measurement by inductively coupled plasma-mass spectrometry. Subjects were followed up and divided into two groups (preterm and full-term deliveries) according to duration of gestation.
  
  
  RESULTS
  The average (range) and geometric means of blood lead levels were 3.8 (1.0-20.5) and 3.5 μg/dl, respectively. Blood lead level was significantly (p<0.05) higher in mothers who delivered preterm babies than in those who delivered full-term babies (mean±SD: 4.46±1.86 and 3.43±1.22 μg/dl, respectively). Logistic regression analysis demonstrated that a 1 unit increase in blood lead levels led to an increased risk of preterm birth (OR 1.41, 95% CI 1.08 to 1.84).
  
  
  CONCLUSIONS
  Adverse pregnancy outcomes may occur at blood lead concentrations below the current acceptable level.
authors.affiliation: National Institute of Occupational Safety and Health, 6-21-6 Nagao, Tama-ku, Kawasaki 214-8585, Japan. vigeh@h.jniosh.go.jp
authors.forename: Mohsen
authors.initials: M
authors.lastname: Vigeh
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Zahrabigom
authors.initials: Z
authors.lastname: Seyedaghamiri
authors.forename: Atsuko
authors.initials: A
authors.lastname: Shinohara
authors.forename: Takehisa
authors.initials: T
authors.lastname: Matsukawa
authors.forename: Momoko
authors.initials: M
authors.lastname: Chiba
authors.forename: Masoud
authors.initials: M
authors.lastname: Yunesian
mesh_terms: D000293:Adolescent; D000328:Adult; D001800:Blood Specimen Collection / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects; D008431:Maternal-Fetal Exchange; D007752:Obstetric Labor, Premature / Q000097:blood / Q000139:chemically induced*; D011247:Pregnancy; D055815:Young Adult
chemical_list: D007854:Lead