title: Low-level lead exposure and elevations in blood pressure during pregnancy.
abstract: BACKGROUND
  Lead exposure is associated with elevated blood pressure during pregnancy; however, the magnitude of this relationship at low exposure levels is unclear.
  
  
  OBJECTIVE
  Our goal was to determine the association between low-level lead exposure and blood pressure during late pregnancy.
  
  
  METHODS
  We collected admission and maximum (based on systolic) blood pressures during labor and delivery among 285 women in Baltimore, Maryland. We measured umbilical cord blood lead using inductively coupled plasma mass spectrometry. Multivariable models were adjusted for age, race, median household income, parity, smoking during pregnancy, prepregnancy body mass index, and anemia. These models were used to calculate benchmark dose values.
  
  
  RESULTS
  Geometric mean cord blood lead was 0.66 μg/dL (95% confidence interval, 0.61-0.70). Comparing blood pressure measurements between those in the highest and those in the lowest quartile of lead exposure, we observed a 6.87-mmHg (1.51-12.21 mmHg) increase in admission systolic blood pressure and a 4.40-mmHg (0.21-8.59 mmHg) increase in admission diastolic blood pressure after adjustment for confounders. Corresponding values for maximum blood pressure increase were 7.72 (1.83-13.60) and 8.33 (1.14-15.53) mmHg. Benchmark dose lower limit values for a 1-SD increase in blood pressure were < 2 μg/dL blood lead for all blood pressure end points.
  
  
  CONCLUSIONS
  A significant association between low-level lead exposures and elevations in maternal blood pressure during labor and delivery can be observed at umbilical blood lead levels < 2 μg/dL.
authors.affiliation: Department of Environmental Health Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Wells
authors.forename: Ana
authors.initials: A
authors.lastname: Navas-Acien
authors.forename: Julie B
authors.initials: JB
authors.lastname: Herbstman
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Apelberg
authors.forename: Ellen K
authors.initials: EK
authors.lastname: Silbergeld
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Caldwell
authors.forename: Robert L
authors.initials: RL
authors.lastname: Jones
authors.forename: Rolf U
authors.initials: RU
authors.lastname: Halden
authors.forename: Frank R
authors.initials: FR
authors.lastname: Witter
authors.forename: Lynn R
authors.initials: LR
authors.lastname: Goldman
mesh_terms: D000293:Adolescent; D000328:Adult; D015142:Baltimore; D001794:Blood Pressure / Q000187:drug effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007854:Lead / Q000633:toxicity*; D008396:Maryland; D011247:Pregnancy; D055815:Young Adult
chemical_list: D007854:Lead