title: Phthalates and perfluorooctanesulfonic acid in human amniotic fluid: temporal trends and timing of amniocentesis in pregnancy.
abstract: BACKGROUND
  Measures of prenatal environmental exposures are important, and amniotic fluid levels may directly reflect fetal exposures during hypothesized windows of vulnerability.
  
  
  OBJECTIVE
  We aimed to detect various phthalate metabolites and perfluorooctanesulfonic acid (PFOS) in human amniotic fluid, to study temporal exposure trends, and to estimate potential associations with gestational week of amniocentesis and maternal age and parity at amniocentesis.
  
  
  METHODS
  We studied 300 randomly selected second-trimester amniotic fluid samples from a Danish pregnancy-screening biobank covering 1980 through 1996. We used only samples from male offspring pregnancies. We assayed the environmental pollutants by liquid chromatography/triple quadrupole mass spectrometry and analyzed data using generalized linear regression models.
  
  
  RESULTS
  We detected the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) at a median concentration of 0.27 ng/mL [interquartile range (IQR): 0.20-0.37 ng/mL], the diisononyl phthalate (DiNP) metabolite mono(4-methyl-7-carboxyheptyl) phthalate (7cx-MMeHP) at 0.07 ng/mL (IQR: 0.05-0.11 ng/mL), and PFOS at 1.1 ng/mL (IQR: 0.66-1.60 ng/mL). An increase of 1 calendar year was associated with 3.5% lower [95% confidence interval (CI): -4.8%, -2.1%] 5cx-MEPP levels and with 7.1% higher (95% CI: 5.3%, 9.0%) 7cx-MMeHP levels. For each later gestational week of amniocentesis, 5cx-MEPP was 9.9% higher (95% CI: 4.8%, 15.2%), 7cx-MMeHP was 8.6% higher (95: CI: 2.7%, 14.9%), and PFOS was 9.4% higher (95: CI: 3.3%, 15.9%). We observed no associations with maternal age or parity.
  
  
  CONCLUSIONS
  Measured metabolite levels appeared to parallel decreasing DEHP exposure and increasing DiNP exposure during the study period. The environmental pollutant levels were positively associated with later gestational age at amniocentesis during pregnancy weeks 12-22.
authors.affiliation: Danish Ramazzini Centre, Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark. morten@sondergaard-jensen.dk
authors.forename: Morten Søndergaard
authors.initials: MS
authors.lastname: Jensen
authors.forename: Bent
authors.initials: B
authors.lastname: Nørgaard-Pedersen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Toft
authors.forename: David M
authors.initials: DM
authors.lastname: Hougaard
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Arieh
authors.initials: A
authors.lastname: Cohen
authors.forename: Ane Marie
authors.initials: AM
authors.lastname: Thulstrup
authors.forename: Richard
authors.initials: R
authors.lastname: Ivell
authors.forename: Ravinder
authors.initials: R
authors.lastname: Anand-Ivell
authors.forename: Christian H
authors.initials: CH
authors.lastname: Lindh
authors.forename: Bo A G
authors.initials: BA
authors.lastname: Jönsson
mesh_terms: D017738:Alkanesulfonic Acids / Q000032:analysis*; D000649:Amniocentesis / Q000379:methods*; D000653:Amniotic Fluid / Q000737:chemistry*; D002853:Chromatography, Liquid; D003718:Denmark; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D005466:Fluorocarbons / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D016014:Linear Models; D008297:Male; D013058:Mass Spectrometry; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D010795:Phthalic Acids / Q000032:analysis*; D011247:Pregnancy
chemical_list: D017738:Alkanesulfonic Acids; D004785:Environmental Pollutants; D005466:Fluorocarbons; D010795:Phthalic Acids; C076994:perfluorooctane sulfonic acid