title: Is there a role for preparatory cycle in ovum donation recipients?
abstract: OBJECTIVE
  In ovum donation cycles, the role of preparatory cycles to ensure proper endometrial development in the recipient remains controversial. As evidenced in the literature, endometrial receptivity is critical in conception. Therefore, endometrial preparation with exogenous hormones in addition to synchronization of the recipient and donor are essential in achieving a successful outcome.
  
  
  RESULTS
  There are very limited data specifically examining the benefit of recipients undergoing preparatory cycles prior to their actual egg donation cycle. One study concluded that trial hormone replacement treatment cycles with endometrial biopsies may be useful in older reproductive-age women but not in younger women. Another study showed no difference in pregnancy rates between those who did and did not undergo preparatory cycles.
  
  
  CONCLUSIONS
  Since one of the integral elements of preparatory cycles is determining endometrial dating, with relatively conflicting data, these mock cycles may not be as beneficial as expected. Therefore, for those who routinely use preparatory cycles, the potential risks, benefits, and costs of these cycles, increased hormonal exposure, the relatively invasive nature of the procedure, and time prior to performing them must be considered.
authors.affiliation: Stanford University Medical Center, 300 Pasteur, Dr. HH333, Stanford, California 94305, USA.
authors.forename: Sunny H
authors.initials: SH
authors.lastname: Jun
authors.forename: Mark D
authors.initials: MD
authors.lastname: Hornstein
mesh_terms: D004717:Endometrium / Q000187:drug effects*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D004966:Estrogens, Conjugated (USP) / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects*; D018587:Oocyte Donation / Q000379:methods*; D011292:Premedication; D011372:Progestins / Q000494:pharmacology* / Q000627:therapeutic use; D027724:Reproductive Techniques, Assisted
chemical_list: D004966:Estrogens, Conjugated (USP); D011372:Progestins; D004958:Estradiol