title: Pregnancy and implantation rates in normal replacement versus stimulated cycles.
abstract: The relative importance that endometrial development and embryo quality have on implantation rates achieved with assisted reproductive technology (ART) is the subject of controversy. Ovarian stimulation has been repeatedly mentioned as having a detrimental effect on endometrial receptivity (Paulson et al., 1990, Fertil. Steril., 53, 870-874). We compared pregnancy and implantation rates achieved with ART during stimulated cycles and hormonal replacement cycles, in patients matched for the following criteria: age < 35 years for the patient donating oocytes; transfer of at least two good quality embryos/oocytes and good quality transfer. All transfer cases performed during hormonal replacement cycles were done with donated oocytes. Comparison of results between techniques was not attempted due to potential differences in populations. The pregnancy and implantation rates achieved with each technique during stimulated and hormonal replacement cycles were not statistically different. In contradiction to previous results, our data suggest that differences in uterine receptivity between stimulated and hormonal replacement cycles in the age group studied are not of critical importance in embryo implantation. Good embryo quality appears to be the dominant factor in determining the success of ART.
authors.affiliation: Department of Obstetrics and Gynecology, University of California, Irvine Medical Center, Orange 92613-1491.
authors.forename: L
authors.initials: L
authors.lastname: Bernardini
authors.forename: V
authors.initials: V
authors.lastname: Alam
authors.forename: R H
authors.initials: RH
authors.lastname: Asch
authors.forename: J P
authors.initials: JP
authors.lastname: Balmaceda
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000627:therapeutic use; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use*; D015181:Gamete Intrafallopian Transfer; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000627:therapeutic use; D006062:Gonadotropins / Q000627:therapeutic use*; D006801:Humans; D008596:Menotropins / Q000627:therapeutic use*; D011247:Pregnancy; D012099:Reproductive Techniques; D012189:Retrospective Studies; D017388:Zygote Intrafallopian Transfer
chemical_list: D006063:Chorionic Gonadotropin; D006062:Gonadotropins; D007987:Gonadotropin-Releasing Hormone; D008596:Menotropins; D005640:Follicle Stimulating Hormone