title: Effects of the intensity of downregulation on outcome of in vitro fertilization and embryo transfer.
abstract: Gonadotropin releasing hormone agonists (GnRHa) are commonly used during in vitro fertilization and embryo transfer (IVF/ET) treatment cycles to downregulate the hypothalamic-pituitary-ovarian axis prior to ovarian stimulation with gonadotropins. It has been suggested that profound downregulation may have an adverse effect on IVF/ET outcome. The aim of this study was to examine the relationship between the degree of downregulation and IVF/ET outcome. A retrospective analysis was performed on 151 IVF/ET cycles conducted over a six month period. Intensity of downregulation was assessed using measurements of serum concentrations of luteinizing hormone (LH) and estradiol (E2) made at the end of a two week downregulation period. There was no correlation between serum concentration of LH (whether used alone or in combination with E2) and IVF/ET pregnancy rates. However, those subjects who were more suppressed according to the E2 concentration (< 148 pmol/l, [median]) required significantly more gonadotropins (3306 IU versus 2863 IU, p < 0.05) and took longer for follicles to reach maturity (10.9 days versus 9.7 days, p < 0.05). They also had a lower pregnancy rate per embryo transfer (10.4% versus 28.6%, p < 0.05) compared with those having a higher basal E2 concentration. We conclude from this study that the basal serum E2 concentration rather than the LH concentration is a more sensitive indicator of the intensity of downregulation by GnRHa and it may be a better predictor of IVF outcome.
authors.affiliation: Department of Obstetrics and Gynecology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
authors.forename: P M
authors.initials: PM
authors.lastname: Lam
authors.forename: L P
authors.initials: LP
authors.lastname: Cheung
authors.forename: C M Y
authors.initials: CM
authors.lastname: Choy
authors.forename: Y P
authors.initials: YP
authors.lastname: Lau
authors.forename: C
authors.initials: C
authors.lastname: Haines
mesh_terms: D000328:Adult; D002064:Buserelin / Q000008:administration & dosage / Q000009:adverse effects; D004624:Embryo Transfer; D004958:Estradiol / Q000097:blood; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects; D005307:Fertilization in Vitro; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects* / Q000502:physiology; D007986:Luteinizing Hormone / Q000097:blood; D010053:Ovary / Q000187:drug effects* / Q000502:physiology; D010902:Pituitary Gland / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D005300:Fertility Agents, Female; D004958:Estradiol; D007986:Luteinizing Hormone; D002064:Buserelin