title: Exposure to phytoestrogens in utero and age at menarche in a contemporary British cohort.
abstract: Phytoestrogens are estrogenic compounds that occur naturally in plants. Phytoestrogens can cross the placenta, and animal studies have found associations between in utero exposure to phytoestrogens and markers of early puberty. We investigated the association between in utero exposure to phytoestrogens and early menarche (defined as <11.5 years of age at onset) using data from a nested case-control study within the Avon Longitudinal Study of Parents and Children, a longitudinal study involving families living in the South West of England. Concentrations of six phytoestrogens were measured in maternal urine samples collected during pregnancy. Logistic regression was used to explore associations between tertiles of phytoestrogen concentrations and menarche status, with adjustment for maternal age at menarche, maternal education, pre-pregnancy body mass index (BMI), child birth order, duration of breastfeeding, and gestational age at sample collection. Among 367 mother-daughter dyads, maternal median (interquartile range) creatinine-corrected concentrations (in µg/g creatinine) were: genistein 62.1 (27.1-160.9), daidzein 184.8 (88.8-383.7), equol 4.3 (2.8-9.0), O-desmethylangolensin (O-DMA) 13.0 (4.4-34.5), enterodiol 76.1 (39.1-135.8), and enterolactone 911.7 (448.1-1558.0). In analyses comparing those in the highest tertile relative to those in the lowest tertile of in utero phytoestrogen exposure, higher enterodiol levels were inversely associated with early menarche (odds ratio (OR)=0.47; 95% confidence interval (CI): 0.26-0.83), while higher O-DMA levels were associated with early menarche (OR=1.89; 95% CI: 1.04-3.42). These findings suggest that in utero exposure to phytoestrogens may be associated with earlier age at menarche, though the direction of association differs across phytoestrogens.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Rd NE, Atlanta, GA 30322, United States; National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Atlanta, GA 30341, United States. Electronic address: kristin.marks@emory.edu.
authors.forename: Kristin J
authors.initials: KJ
authors.lastname: Marks
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Rd NE, Atlanta, GA 30322, United States; National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Atlanta, GA 30341, United States.
authors.forename: Terryl J
authors.initials: TJ
authors.lastname: Hartman
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Atlanta, GA 30341, United States.
authors.forename: Ethel V
authors.initials: EV
authors.lastname: Taylor
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Atlanta, GA 30341, United States.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Rybak
authors.affiliation: The National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care West (NIHR CLAHRC West) at University Hospitals Bristol NHS Foundation Trust, 9th Floor, White Friars, Lewins Mead, Bristol BS1 2NT, United Kingdom; School of Social and Community Medicine, University of Bristol, 39 Whatley Road, Bristol BS8 2PS, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Northstone
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Rd NE, Atlanta, GA 30322, United States.
authors.forename: Michele
authors.initials: M
authors.lastname: Marcus
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D004739:England / Q000453:epidemiology; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008431:Maternal-Fetal Exchange; D008572:Menarche; D016017:Odds Ratio; D048789:Phytoestrogens / Q000652:urine*; D011247:Pregnancy / Q000652:urine; D011297:Prenatal Exposure Delayed Effects
chemical_list: D048789:Phytoestrogens
keywords: ALSPAC; Endocrine disruptors; Menarche; Phytoestrogens; Puberty