title: Endocrine disruptors and spontaneous premature labor: a case control study.
abstract: BACKGROUND
  Premature labor is a poorly understood condition. Estrogen is thought to play a key role and therefore the labor process may be affected by endocrine disruptors. We sought to determine whether or not an environmental toxicant, DDE, or dietary derived endocrine disruptors, daidzein and genistein, are associated with spontaneous preterm labor.
  
  
  METHODS
  Cases were defined as primiparous patients having a preterm delivery at or before 35 weeks following the spontaneous onset of labor. Controls were defined as primiparous women who delivered on the same day as the cases but at term gestation. Over approximately 1 year, 26 cases and 52 controls were recruited. Subjects agreed to have blood tests on day one postpartum for DDE and for the phytoestrogens genistein and daidzein.
  
  
  RESULTS
  The mean concentration of DDE was similar in the case and control groups: 4.29 vs 4.32 ng/g lipid p = .85. In the case group, 13/26 had detectable levels of daidzein (range 0.20 - 1.56 ng/ml) compared to 25/52 controls (range 0.21 - 3.26 ng/ml). The mean concentration of daidzein was similar in cases compared to controls: 0.30 vs .34 ng/ml p = 0.91. Of the case group,14/26 had detectable levels of genistein (range 0.20 - 2.19 ng/ml) compared to 32/52 controls (range 0.21 - 2.55 ng/ml). The mean concentration of genistein was similar in cases compared to controls: 0.39 vs 0.31 ng/ml, p = 0.61.
  
  
  CONCLUSIONS
  The serum levels of DDE in this population were found to be low. There appears to be no relationship between serum concentrations of DDE, daidzein, and genistein and spontaneous preterm labor in our population. The inability to identify an effect may be related to the comparatively low concentrations of DDE in our population and the rapid and variable reduction of phytoestrogens from women in labor.
authors.affiliation: Department of Obstetrics and Gynecology and Community Health Sciences, University of Calgary, 1403 29th St NW Calgary Alberta Canada. stephen.wood@calgaryhealthregion.ca
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Wood
authors.forename: John J
authors.initials: JJ
authors.lastname: Jarrell
authors.forename: Cheryl
authors.initials: C
authors.lastname: Swaby
authors.forename: Sui
authors.initials: S
authors.lastname: Chan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D052244:Endocrine Disruptors / Q000097:blood* / Q000633:toxicity; D004781:Environmental Exposure; D005260:Female; D019833:Genistein / Q000097:blood* / Q000633:toxicity; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007529:Isoflavones / Q000097:blood* / Q000633:toxicity; D007752:Obstetric Labor, Premature / Q000097:blood* / Q000139:chemically induced; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012016:Reference Values
chemical_list: D052244:Endocrine Disruptors; D007529:Isoflavones; C004742:daidzein; D019833:Genistein