Adverse effects of maternal lead levels on birth outcomes in the ALSPAC study: a prospective birth cohort study.
OBJECTIVE
To study the associations of prenatal blood lead levels (B-Pb) with pregnancy outcomes in a large cohort of mother-child pairs in the UK.


METHODS
Prospective birth cohort study.


METHODS
Avon area of Bristol, UK.


METHODS
Pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC).


METHODS
Whole blood samples were collected and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Data collected on the infants included anthropometric variables and gestational age at delivery. Linear regression models for continuous outcomes and logistic regression models for categorical outcomes were adjusted for covariates including maternal height, smoking, parity, sex of the baby and gestational age.


METHODS
Birthweight, head circumference and crown-heel length, preterm delivery and low birthweight.


RESULTS
The mean blood lead level (B-Pb) was 3.67 ± 1.47 μg/dl. B-Pb ≥ 5 μg/dl significantly increased the risk of preterm delivery (adjusted odds ratio [OR] 2.00 95% confidence interval [95% CI] 1.35-3.00) but not of having a low birthweight baby (adjusted OR 1.37, 95% CI 0.86-2.18) in multivariable binary logistic models. Increasing B-Pb was significantly associated with reductions in birth weight (β -13.23, 95% CI -23.75 to -2.70), head circumference (β -0.04, 95% CI -0.07 to -0.06) and crown-heel length (β -0.05, 95% CI -0.10 to -0.00) in multivariable linear regression models.


CONCLUSIONS
There was evidence for adverse effects of maternal B-Pb on the incidence of preterm delivery, birthweight, head circumference and crown-heel length, but not on the incidence of low birthweight, in this group of women.
Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK.
C M
CM
Taylor
J
J
Golding
A M
AM
Emond
D000328:Adult; D001724:Birth Weight; D015331:Cohort Studies; D004785:Environmental Pollutants / Q000009:adverse effects / Q000097:blood*; D005260:Female; D005317:Fetal Growth Retardation / Q000139:chemically induced / Q000453:epidemiology; D059647:Gene-Environment Interaction; D006801:Humans; D007231:Infant, Newborn; D007854:Lead / Q000097:blood* / Q000633:toxicity; D007855:Lead Poisoning / Q000150:complications / Q000453:epidemiology*; D008137:Longitudinal Studies; D008297:Male; 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; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology
D004785:Environmental Pollutants; D007854:Lead
Birthweight; head circumference; lead; low birthweight; pregnancy; preterm