title: US assessment of estrogen-responsive organ growth among healthy term infants: piloting methods for assessing estrogenic activity.
abstract: BACKGROUND
  A mother's circulating estrogen increases over the third trimester, producing physiological effects on her newborn that wane postnatally. Estrogenization might be prolonged in newborns exposed to exogenous estrogens, such as isoflavones in soy formula.
  
  
  OBJECTIVE
  We evaluated ultrasonography for monitoring growth of multiple estrogen-responsive organs in healthy infants and developed organ-growth trajectories.
  
  
  METHODS
  We studied 38 boys (61 visits) from birth to age 6 months and 41 girls (96 visits) from birth to age 1 year using a partly cross-sectional, partly longitudinal design. We measured uterus and ovaries in girls, testes and prostate in boys, and kidneys, breasts, thymus, and thyroid in all children. We imaged all organs from the body surface in one session of < 1 h.
  
  
  RESULTS
  Uterine volume decreased from birth (P < 0.0001), whereas ovarian volume increased sharply until age 2 months and then decreased (P < 0.001). Testicular volume increased with age (P < 0.0001), but prostatic volume showed minimal age trend. Breast bud diameter showed no age trend in girls but declined from birth in boys (P = 0.03).
  
  
  CONCLUSIONS
  US examination of multiple estrogen-responsive organs in infants in a single session is feasible and yields volume estimates useful for assessing potential endocrine disruptor effects on organ growth.
authors.affiliation: Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Ruby H N
authors.initials: RH
authors.lastname: Nguyen
authors.forename: David M
authors.initials: DM
authors.lastname: Umbach
authors.forename: Richard B
authors.initials: RB
authors.lastname: Parad
authors.forename: Berrit
authors.initials: B
authors.lastname: Stroehla
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Rogan
authors.forename: Judy A
authors.initials: JA
authors.lastname: Estroff
mesh_terms: D000818:Animals; D002417:Cattle; D002657:Child Development; D003430:Cross-Sectional Studies; D052244:Endocrine Disruptors / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008892:Milk; D008895:Milk, Human; D010053:Ovary / Q000000981:diagnostic imaging* / Q000187:drug effects*; D048789:Phytoestrogens / Q000494:pharmacology*; D010865:Pilot Projects; D011467:Prostate / Q000000981:diagnostic imaging* / Q000187:drug effects*; D012044:Regression Analysis; D045730:Soy Foods; D013737:Testis / Q000000981:diagnostic imaging* / Q000187:drug effects*; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging* / Q000187:drug effects*
chemical_list: D052244:Endocrine Disruptors; D004967:Estrogens; D048789:Phytoestrogens