Gestational lead concentrations and timing of menarche in girls enrolled in the Avon Longitudinal Study of Parents and Children

Background. Lead is a persistent, toxic substance and its exposure has been associated with later puberty onset and maturity. Current literature on the role of lead on puberty timing of girls is limited and understanding of mechanisms unclear. Aims. To explore the association of gestational lead concentrations with timing of menarche. Methods. The study population was the Avon Longitudinal Study of Parents and Children. Repeated assessments of menarcheal status were obtained from girls from age 8 through 17. Whole blood samples were obtained in 1991-92 from mothers during the girls’ gestation and lead levels measured using cell mass spectrometry. Potential confounders or effect modifiers considered include: mothers’ education, age at delivery, and smoking during gestation; parity; and the girls’ weight status at age 7. Classification of body mass index (BMI) into healthy or overweight/obese weight status was done using the BMI cutoffs for children developed by the International Obesity Task Force. Data an...