title: Maternal hormones during early pregnancy: a cross-sectional study.
abstract: BACKGROUND
  Little is known about correlates of first-trimester pregnancy hormones as in most studies maternal hormones have been measured later in gestation. We examined the associations of maternal characteristics and child sex with first-trimester maternal concentrations of four hormones implicated in breast cancer: human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), insulin-like growth factor (IGF)-I, and IGF-II.
  
  
  METHODS
  About 338 serum samples donated to the Northern Sweden Maternity Cohort (NSMC), 1975-2001, during the first trimester of uncomplicated pregnancies, were analyzed for the hormones of interest as a part of a case-control study. The associations of maternal characteristics and child sex with hormone concentrations were investigated by correlation, general linear regression, and multivariate regression models.
  
  
  RESULTS
  In the first trimester, greater maternal age was inversely correlated with IGF-I and IGF-II. In comparison with women carrying their first child, already parous women had higher IGF-I but lower hCG. Greater maternal weight and smoking were inversely correlated with hCG. No differences in hormone levels by child sex were observed.
  
  
  CONCLUSIONS
  Our analyses indicated that potentially modifiable maternal characteristics (maternal weight and smoking) influence first-trimester pregnancy maternal hormone concentrations.
authors.affiliation: Division of Cancer Epidemiology, German Cancer Research Center, In Neuenheimer Feld 280, Heidelberg, Germany.
authors.forename: Tianhui
authors.initials: T
authors.lastname: Chen
authors.forename: Eva
authors.initials: E
authors.lastname: Lundin
authors.forename: Kjell
authors.initials: K
authors.lastname: Grankvist
authors.forename: Anne
authors.initials: A
authors.lastname: Zeleniuch-Jacquotte
authors.forename: Marianne
authors.initials: M
authors.lastname: Wulff
authors.forename: Yelena
authors.initials: Y
authors.lastname: Afanasyeva
authors.forename: Helena
authors.initials: H
authors.lastname: Schock
authors.forename: Robert
authors.initials: R
authors.lastname: Johansson
authors.forename: Per
authors.initials: P
authors.lastname: Lenner
authors.forename: Goran
authors.initials: G
authors.lastname: Hallmans
authors.forename: Goran
authors.initials: G
authors.lastname: Wadell
authors.forename: Paolo
authors.initials: P
authors.lastname: Toniolo
authors.forename: Annekatrin
authors.initials: A
authors.lastname: Lukanova
mesh_terms: D000328:Adult; D001835:Body Weight; D006063:Chorionic Gonadotropin / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D000509:alpha-Fetoproteins / Q000378:metabolism*
chemical_list: D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II