title: Steroid hormone levels in pregnancy and 1 year postpartum using isotope dilution tandem mass spectrometry.
abstract: OBJECTIVE
  To establish normal, trimester-specific reference intervals for serum 17beta-estradiol, progesterone (P), 17alpha-hydroxyprogesterone, cortisol, 11-deoxycortisol, androstenedione, DHEA, and DHEAS, measured simultaneously using isotope dilution tandem mass spectrometry.
  
  
  METHODS
  Sequential cohort study.
  
  
  METHODS
  Healthy women undergoing a normal pregnancy (age, 25-38 years; mean, 30 years) attending a prenatal well clinic at gestation weeks 12, 22, and 32 and approximately 1 year postpartum.
  
  
  METHODS
  Trimester-specific reference intervals of endogenous steroid hormones analyzed using an isotope dilution tandem mass spectrometer equipped with an atmospheric pressure photoionization source with deuterium-labeled internal standards.
  
  
  RESULTS
  Serum estradiol, P, 17alpha-hydroxyprogesterone, and 11-deoxycortisol increased throughout pregnancy; cortisol increased up to the second trimester and then remained steady, while androstenedione increased by 80 percent by gestation week 12, then remained constant. Serum DHEA-S decreased by 50% by the third trimester.
  
  
  CONCLUSIONS
  Trimester-specific reference intervals are reported for eight serum steroids. The ratios of individual serum hormone concentrations during pregnancy relative to their 1-year postpartum concentrations illustrate the expected normal trends of changes in hormone concentrations during pregnancy.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University Medical Center, Washington, DC 20057-1465, USA. os35@georgetown.edu
authors.forename: Offie P
authors.initials: OP
authors.lastname: Soldin
authors.forename: Tiedong
authors.initials: T
authors.lastname: Guo
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
authors.forename: Rochelle E
authors.initials: RE
authors.lastname: Tractenberg
authors.forename: Leena
authors.initials: L
authors.lastname: Hilakivi-Clarke
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Soldin
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D012739:Gonadal Steroid Hormones / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D006801:Humans; D007554:Isotopes; D049590:Postpartum Period / Q000097:blood* / Q000378:metabolism; D011247:Pregnancy / Q000097:blood* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D012739:Gonadal Steroid Hormones; D007554:Isotopes