title: Hormone-induced delayed ovulation affects early embryonic development.
abstract: OBJECTIVE
  To analyze the effects of delayed ovulation on embryonic development in mice, because intrafollicular oocyte development may be delayed during assisted reproductive technology (ART) treatment in humans.
  
  
  METHODS
  Experimental mouse study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Female C57Bl/6 mice.
  
  
  METHODS
  Cetrorelix is used as a GnRH-antagonist in ART treatments. To assess the effect of delayed ovulation on embryonic development, cetrorelix was applied concomitantly with follicle stimulation by pregnant mare serum gonadotropin. Ovulation was induced by hCG. Controls were stimulated with pregnant mare serum gonadotropin without delaying ovulation. Suppression of ovulation was assessed from the number of tertiary follicles, ruptured follicles, and corpora lutea in mouse ovaries after cetrorelix treatment. Number and weight of embryos and placentas, as well as number of resorption sites and dead embryos, was determined on day 17.5 of pregnancy.
  
  
  METHODS
  Inhibition of ovulation, embryonic development.
  
  
  RESULTS
  Cetrorelix inhibited ovulation in mice, as shown by an increase in number of tertiary follicles concomitant with a significant inhibition of follicle rupture and corpora lutea formation. Delayed ovulation caused by Cetrorelix treatment led to a significant increase in resorption sites and a significant decrease in embryonic weight of offspring.
  
  
  CONCLUSIONS
  Preovulatory oocyte overripeness might have an effect on fertility and embryonic development during ART treatment.
authors.affiliation: Institute of Molecular Biology, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
authors.forename: Ann-Kathrin
authors.initials: AK
authors.lastname: Bittner
authors.forename: Bernhard
authors.initials: B
authors.lastname: Horsthemke
authors.forename: Elke
authors.initials: E
authors.lastname: Winterhager
authors.forename: Ruth
authors.initials: R
authors.lastname: Grümmer
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D010064:Embryo Implantation / Q000187:drug effects; D020964:Embryo Loss / Q000139:chemically induced; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D005298:Fertility / Q000187:drug effects; D005300:Fertility Agents, Female / Q000009:adverse effects / Q000494:pharmacology*; D005865:Gestational Age; D007987:Gonadotropin-Releasing Hormone / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006727:Hormone Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000009:adverse effects / Q000379:methods*; D010920:Placenta / Q000187:drug effects; D010929:Placentation; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D006064:Gonadotropins, Equine; D006727:Hormone Antagonists; D007987:Gonadotropin-Releasing Hormone; C062876:cetrorelix