title: Gender specific chronological and morphometric assessment of fetal bladder wall development.
abstract: OBJECTIVE
  To enhance our understanding of sonographically visible alterations in bladder wall thickness, we delineated phenotypic changes occurring in developing smooth muscle cells of the fetal and postnatal bladder with respect to gender specific differences.
  
  
  METHODS
  Bladders of 30 male and 18 female fetuses and 4 stillborn infants were immunostained with an alpha-smooth muscle actin antibody. Morphological and morphometric assessment was performed with the assistance of an image analysis system.
  
  
  RESULTS
  Alpha-smooth muscle actin expression in fetal bladder wall was detectable at 9 weeks of gestation. Bladder wall thickness and mean profile area of smooth muscle bundles increased significantly with advancing gestation, mediated by linear growth patterns. Fetal bladder wall development occurred uniformly, unrelated to gender.
  
  
  CONCLUSIONS
  Although the lower urinary tract emerges in a gender specific way, our results suggest that in normal fetal growth detrusor muscle formation proceeds independent of genital sex.
authors.affiliation: Department of Pediatric Urology, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria.
authors.forename: Iris
authors.initials: I
authors.lastname: Koerner
authors.forename: M
authors.initials: M
authors.lastname: Deibl
authors.forename: J
authors.initials: J
authors.lastname: Oswald
authors.forename: C
authors.initials: C
authors.lastname: Schwentner
authors.forename: A
authors.initials: A
authors.lastname: Lunacek
authors.forename: Helga
authors.initials: H
authors.lastname: Fritsch
authors.forename: Georg
authors.initials: G
authors.lastname: Bartsch
authors.forename: Christian
authors.initials: C
authors.lastname: Radmayr
mesh_terms: D000199:Actins / Q000378:metabolism; D000653:Amniotic Fluid; D005260:Female; D005333:Fetus / Q000196:embryology*; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000196:embryology* / Q000378:metabolism; D012737:Sex Factors; D001743:Urinary Bladder / Q000196:embryology* / Q000378:metabolism
chemical_list: D000199:Actins