title: Human chorionic gonadotropin in human placentas from normal and preeclamptic pregnancies.
abstract: OBJECTIVE
  The aim of this study was to examine the distribution of human chorionic gonadotropin (hCG) in the human placenta of normotensive and preeclamptic pregnancies and to determine by computer image analysis, whether differences in hCG immunoreactivity occurred in preeclamptic as apposed to normotensive pregnancies. We discuss how far elevated maternal serum levels of hCG normally observed in preeclamptic patients reflect an increased secretory activity of the syncytiotrophoblast.
  
  
  METHODS
  We used the immunoperoxidase technique to locate hCG. Quantification of immunostaining intensity was done by computer image analysis.
  
  
  RESULTS
  In normotensive placentas from all the gestational ages human chorionic gonadotrophin immunoreactivity was specifically detected in the syncytiotrophoblast. There is an apparent decrease in the intensity of the hCG immunostaining in the syncytiotrophoblast from the 29th to 36th week of gestation in normotensive placentas. No hCG immunostaining was observed in the villous or extravillous cytotrophoblast of all placentas. In preeclamptic placentas the expression of hCG was homogeneous with a moderate to intense immunoreactivity in the syncytiotrophoblast. Microdensitometric analysis of the section from normotensive and preeclamptic placentas indicated that there is a statistically significant preeclampsia-induced increase in immunohistochemical reaction intensity for hCG (p < 0.05).
  
  
  CONCLUSIONS
  This study seems to demonstrate that increased production of hCG by preeclamptic placentas is associated with strong hCG immunostaining of the syncytiotrophoblast.
authors.affiliation: Instituto de Histologia e Embriologia, Faculdade de Medicina de Coimbra, Universidade de Coimbra, Portugal. josebarros.3@netc.pt
authors.forename: J S
authors.initials: JS
authors.lastname: Barros
authors.forename: M G
authors.initials: MG
authors.lastname: Baptista
authors.forename: V A
authors.initials: VA
authors.lastname: Bairos
mesh_terms: D006063:Chorionic Gonadotropin / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D012016:Reference Values; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin