title: Exposure to polyfluoroalkyl chemicals during pregnancy is not associated with offspring age at menarche in a contemporary British cohort.
abstract: BACKGROUND
  Polyfluoroalkyl chemicals (PFCs) are commercially synthesized chemicals used in consumer products. Exposure to certain PFCs is widespread, and some PFCs may act as endocrine disruptors. We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) in the United Kingdom to conduct a nested case-control study examining the association between age at menarche, and exposure to PFCs during pregnancy.
  
  
  METHODS
  Cases were selected from female offspring in the ALSPAC who reported menarche before the age of 11.5 years (n = 218), and controls were a random sample of remaining girls (n = 230). Serum samples taken from the girls' mothers during pregnancy (1991-1992) were analyzed using on-line solid-phase extraction coupled to isotope dilution high-performance liquid chromatography-tandem mass spectrometry for 8 PFCs. Logistic regression was used to determine association between maternal serum PFC concentrations, and odds of earlier age at menarche.
  
  
  RESULTS
  PFOS and PFOA were the predominant PFCs (median serum concentrations of 19.8 ng/mL and 3.7 ng/mL). All but one PFC were detectable in most samples. Total PFC concentration varied by number of births (inverse association with birth order; p-value < 0.0001) and race of the child (higher among whites; p-value = 0.03). The serum concentrations of carboxylates were associated with increased odds of earlier age at menarche; concentrations of perfluorooctane sulfonamide, the sulfonamide esters and sulfonates were all associated with decreased odds of earlier age at menarche. However, all confidence intervals included the null value of 1.0.
  
  
  CONCLUSIONS
  ALSPAC study participants had nearly ubiquitous exposure to most PFCs examined, but PFC exposure did not appear to be associated with altered age at menarche of their offspring.
authors.affiliation: Epidemiology Department, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Krista Yorita
authors.initials: KY
authors.lastname: Christensen
authors.forename: Mildred
authors.initials: M
authors.lastname: Maisonet
authors.forename: Carol
authors.initials: C
authors.lastname: Rubin
authors.forename: Adrianne
authors.initials: A
authors.lastname: Holmes
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.forename: Kayoko
authors.initials: K
authors.lastname: Kato
authors.forename: W Dana
authors.initials: WD
authors.lastname: Flanders
authors.forename: Jon
authors.initials: J
authors.lastname: Heron
authors.forename: Michael A
authors.initials: MA
authors.lastname: McGeehin
authors.forename: Michele
authors.initials: M
authors.lastname: Marcus
mesh_terms: D000328:Adult; D017738:Alkanesulfonic Acids / Q000032:analysis; D002210:Caprylates / Q000097:blood; D002648:Child; D015331:Cohort Studies; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D005466:Fluorocarbons / Q000032:analysis / Q000097:blood* / Q000633:toxicity; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D008572:Menarche / Q000187:drug effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D052616:Solid Phase Extraction; D006113:United Kingdom; D055815:Young Adult
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid