Critical windows of fetal lead exposure: adverse impacts on length of gestation and risk of premature delivery.
OBJECTIVE
Research on the role of environmental lead exposure in the complex etiology of premature birth has yielded inconsistent results. We assessed the trimester-specific effect of prenatal lead exposure on gestational age and risk of premature delivery.


METHODS
We used linear and logistic regression to identify critical windows of susceptibility to lead exposure on gestational length.


RESULTS
In single-trimester models, decreases in gestational length were most strongly associated with first and second trimester blood lead. In adjusted logistic regression models, a one-standard deviation increase in second trimester blood lead was associated with an odds ratio of prematurity of 1.75 (95% CI: 1.02, 3.02).


CONCLUSIONS
Maternal whole blood lead levels measured during first and second trimesters yielded the most prominent inverse association with length of gestation and increased the risk of prematurity.
Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory Street, Ann Arbor, MI 48109, USA. dcantonw@umich.edu
David
D
Cantonwine
Howard
H
Hu
Brisa N
BN
Sánchez
Héctor
H
Lamadrid-Figueroa
Donald
D
Smith
Adrienne S
AS
Ettinger
Adriana
A
Mercado-García
Mauricio
M
Hernández-Avila
Robert O
RO
Wright
Martha Maria
MM
Téllez-Rojo
D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007854:Lead / Q000009:adverse effects* / Q000097:blood; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects*; D008800:Mexico / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011264:Pregnancy Trimesters; D047928:Premature Birth / Q000139:chemically induced* / Q000453:epidemiology*; D012307:Risk Factors; D055815:Young Adult
D015415:Biomarkers; D007854:Lead