Comparison of low-dose human menopausal gonadotropin and micronized 17β-estradiol supplementation in in vitro maturation cycles with thin endometrial lining

ObjectiveA challenge of in vitro maturation (IVM) treatment in some women is insufficient development of the endometrium prior to embryo transfer.DesignRetrospective study.SettingMcGill Reproductive Center, Montreal, Canada.Patient(s)Women with endometrial thickness <6 mm on days 6–10 ultrasound (US) scan of IVM treatment.Intervention(s)In the human menopausal gonadotropin (hMG) group, 150 IU/day of hMG was started and in the estradiol group, 6 to 12 mg/day of micronized 17β-estradiol was initiated. Additional US scans were performed 2 to 3 days apart, until endometrial thickness reached ≥8 mm or a dominant follicle (>10 mm) was identified.Main Outcome Measure(s)Endometrial lining before oocyte retrival.Result(s)In both groups endometrial lining significantly thickened following treatment. However, hMG treatment resulted in a higher number of follicles ≥7 mm compared to estradiol (7.4 ± 4.8 vs. 3.4 ± 2.5, respectively) and a significantly higher percentage of mature oocytes that were identified on the day of oocyte retrieval (in vivo matured oocytes) (15.1% vs. 10.5%).Conclusion(s)In IVM designated cycles with a thin endometrium both low-dose hMG and micronized 17β-estradiol supplementation significantly improve endometrial thickness. However, low-dose hMG results in larger follicles and a greater number of in vivo matured oocytes.