title: Intramuscular route of progesterone administration increases pregnancy rates during non-downregulated frozen embryo transfer cycles.
abstract: OBJECTIVE
  The optimal route of progesterone (P4) administration in embryo transfer (FET) cycles remains to be determined. The objective of this study is to compare the pregnancy outcomes between intramuscular (IM) and vaginal progesterone (PV) administration for endometrial preparation in non-donor FET cycles.
  
  
  METHODS
  A retrospective clinical study in a private practice infertility setting.
  
  
  RESULTS
  No significant differences in patient demographics and embryo characteristics were noted between the two groups. The clinical pregnancy rate as well as the live birth rate were significantly higher in the IM arm compared to the PV arm (38.2% vs 28%, 34.5 % vs 22.8%, respectively).
  
  
  CONCLUSIONS
  Although both routes of progesterone administration had similar rates of initial positive pregnancy tests, the IM route had a significantly higher live birth rate. The exact reason for this difference remains to be determined.
authors.affiliation: University of Cincinnati Medical Center, Cincinnati, OH, USA. haddadgus@gmail.com
authors.forename: Ghassan
authors.initials: G
authors.lastname: Haddad
authors.forename: Docile A
authors.initials: DA
authors.lastname: Saguan
authors.forename: Rose
authors.initials: R
authors.lastname: Maxwell
authors.forename: Michael A
authors.initials: MA
authors.lastname: Thomas
mesh_terms: D000282:Administration, Intravaginal; D000328:Adult; D015925:Cryopreservation; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D050498:Live Birth; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000008:administration & dosage* / Q000097:blood; D012189:Retrospective Studies
chemical_list: D011374:Progesterone