title: Delayed embryo implantation following in vitro fertilization and embryo transfer (IVFET).
abstract: OBJECTIVE
  Our goal was to compare serum human chorionic gonadotropin (hCG) levels in singleton pregnancies achieved following IVFET with those achieved following spontaneous conception.
  
  
  RESULTS
  The mean serum hCG level of patients who became pregnant following IVFET lagged 1.5 days behind that of patients who became pregnant spontaneously.
  
  
  CONCLUSIONS
  The use of gonadotropin releasing hormone analogue as part of the stimulation protocol leading to egg retrieval and IVFET results in a delay in embryo implantation.
authors.affiliation: Reproductive Endocrinology and Infertility Center, Malden Hospital, Massachusetts 02148, USA.
authors.forename: D
authors.initials: D
authors.lastname: Tulchinsky
authors.forename: A
authors.initials: A
authors.lastname: Tulchinsky
authors.forename: V
authors.initials: V
authors.lastname: Paoletti-Falcone
authors.forename: H
authors.initials: H
authors.lastname: Nash
authors.forename: S
authors.initials: S
authors.lastname: Pazdziorko
authors.forename: K
authors.initials: K
authors.lastname: Brown
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood / Q000494:pharmacology; D002996:Clomiphene / Q000494:pharmacology; D010065:Embryo Implantation, Delayed / Q000187:drug effects*; D004624:Embryo Transfer; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006062:Gonadotropins / Q000494:pharmacology; D006801:Humans; D016729:Leuprolide / Q000494:pharmacology*; D011247:Pregnancy
chemical_list: D006063:Chorionic Gonadotropin; D006062:Gonadotropins; D002996:Clomiphene; D016729:Leuprolide