title: In premature luteinization, progesterone induces secretory transformation of the endometrium without impairment of embryo viability.
abstract: OBJECTIVE
  To determine the effect of serum P on endometrial histology in stimulated cycles.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  Community hospital-based donor oocyte program.
  
  
  METHODS
  Fertile young oocyte donors and infertile donor oocyte recipients.
  
  
  METHODS
  Oocyte donors underwent gonadotropin stimulation after midluteal pituitary suppression. Endometrial biopsies were obtained at the time of oocyte retrieval.
  
  
  METHODS
  Endometrial histology and serum P levels in oocyte donors. Pregnancy and implantation rates in oocyte recipients.
  
  
  RESULTS
  Thirteen biopsy specimens (52.0%) showed in-phase mixed proliferative pattern (days 14 to 15), whereas 12 (48.0%) were secretory (days 16 to 17). On the day of hCG, subjects with secretory endometrium had higher P of 1.7 ng/mL (5.4 nmol/L) than women with the mixed pattern (0.8 ng/mL [2.5 nmol/L]). Progesterone > or = 0.9 ng/mL had a 78.6% positive predictive value for secretory transformation. In 75.0% of cycles with secretory endometrium, P was > or = 0.9 ng/mL, (2.9 nmol/L) as early as 2 days before hCG. Both mixed and secretory patterns were associated with similar clinical pregnancy rates (57.1% and 60.0%, respectively) and delivery rates (38.1% and 50.0%, respectively) in recipients.
  
  
  CONCLUSIONS
  Subtle elevation of P induced secretory endometrial transformation without reduction in embryo viability.
authors.affiliation: Alta Bates In Vitro Fertilization Program, Berkeley, California, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Chetkowski
authors.forename: R J
authors.initials: RJ
authors.lastname: Kiltz
authors.forename: W R
authors.initials: WR
authors.lastname: Salyer
mesh_terms: D000328:Adult; D001706:Biopsy; D003338:Corpus Luteum / Q000502:physiology*; D010064:Embryo Implantation; D004717:Endometrium / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle; D008875:Middle Aged; D018587:Oocyte Donation; D011247:Pregnancy; D011256:Pregnancy Outcome; D011374:Progesterone / Q000097:blood*; D011446:Prospective Studies
chemical_list: D011374:Progesterone