title: Luteal phase support does not improve the clinical pregnancy rate of natural cycle frozen-thawed embryo transfer: a retrospective analysis.
abstract: OBJECTIVE
  To evaluate pregnancy outcomes with and without use of luteal phase support (LPS) in frozen-thawed embryo transfer (FET) performed in natural cycles (NC).
  
  
  METHODS
  Retrospective analysis. Before 1st July 2009, two doses of 1500 IU intramuscular human chorionic gonadotrophin were given on the day of FET and 6 days after the transfer. Such practice was stopped after 1st July 2009. The pregnancy outcomes of NC FET with and without LPS were compared.
  
  
  RESULTS
  A total of 408 NC FET cycles were analysed. Demographic data, embryo quality, clinical pregnancy rates and miscarriage rates were comparable with and without LPS. By univariate logistic regression, the only significant factors predicting the clinical pregnancy rate were the women's age, the number of embryos transferred, the number of top quality embryos before and after cryopreservation, and the average number of blastomeres after thawing. Only the women's age (OR 0.944, 95%C.I. 0.893-0.998, p=0.044) remained to be a significant predictor of clinical pregnancy rate by multivariate logistic regression.
  
  
  CONCLUSIONS
  The pregnancy outcomes of NC FET were similar with or without LPS. The women's age was the significant factor affecting the clinical pregnancy rate. A randomised trial should be carried out to confirm the results.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong Special Administrative Region. v200lee@hku.hk
authors.forename: Vivian Chi Yan
authors.initials: VC
authors.lastname: Lee
authors.forename: Raymond Hang Wun
authors.initials: RH
authors.lastname: Li
authors.forename: Ernest Hung Yu
authors.initials: EH
authors.lastname: Ng
authors.forename: William Shu Biu
authors.initials: WS
authors.lastname: Yeung
authors.forename: Pak Chung
authors.initials: PC
authors.lastname: Ho
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D015925:Cryopreservation / Q000379:methods; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy; D008183:Luteal Phase / Q000187:drug effects*; D008423:Maternal Age; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies
chemical_list: D006063:Chorionic Gonadotropin