Value of estrogen pretreatment in patients with diminished ovarian reserve and elevated FSH on a line antagonist regimen: a retrospective controlled study.

Background: The key to enhancing the efficacy of antagonistic regimens in pregnancy is to better synchronize follicular growth during cycles of controlled ovarian stimulation (COS), especially in patients with diminished ovarian reserve (DOR). During in vitro fertilization-embryo transfer (IVF-ET) treatment, luteal phase estrogen pretreatment may enhance follicular development synchronization and yield of mature oocytes. However, the effect of estrogen pretreatment in DOR patients with elevated basal follicle-stimulating hormone (FSH) levels has not been well studied.

Methods: We retrospectively analyzed the clinical data of patients with elevated basal FSH levels and DOR (401 cycles) who underwent IVF/intracytoplasmic monosperm injection (ICSI)-assisted conception. Both groups were treated with a flexible gonadotropin-releasing hormone (GnRH) antagonist regimen and were further divided into two groups according to whether they received luteal estrogen pretreatment. There were 79 patients in the estrogen pretreatment group and 322 patients in the control group. On the second day of the menstrual cycle, gonadotropin (Gn) stimulation of the ovaries was initiated. The general characteristics, clinical, biological parameters and outcomes of the two groups were compared.

Results: The basic profiles of the two groups were similar (P > 0.05). More patients in the pretreatment group showed FSH rebound after gonadotropin (Gn) initiation, resulting in a significantly higher number of Gn days and total Gn than those in the control group (P < 0.05). There was no statistically significant difference in the number of days of antagonist use, follicle output rate (FORT), number of metaphase II(MII)eggs obtained, number of Two pronuclei (2PN) fertilized, number of D₃ quality embryos, blastocyst formation rate, fresh embryo clinical pregnancy rate, cumulative pregnancy rate, and non-transferable embryo rate between the two groups (P > 0.05).

Conclusions: The use of luteal phase estrogen pretreatment in patients with elevated basal FSH combined with DOR resulted in high FSH levels after the release of negative feedback, which was detrimental to early follicular growth, did not increase the follicular output rate, may have increased the use and duration of controlled ovarian stimulation drugs, and did not increase the number of eggs gained or improve clinical outcomes.