Serum estradiol level during withdrawal bleeding as a predictive factor for intermittent ovarian function in women with primary ovarian insufficiency

The objective of this study was to assess the potential predictive factors for follicle growth, ovulation, and pregnancy rate in patients with primary ovarian insufficiency/premature ovarian failure (POI/POF). We enrolled 25 POI patients with desired fertility who were treated and monitored for a minimum of 7 months between the years of 2000-2009 into this retrospective study. The clinical, endocrinologic, chromosomal, and autoimmunologic parameters of these patients were collected. Furthermore, hormonal backgrounds on each of 620 treatment cycles were investigated. The main outcome measures were follicle growth, ovulation, and pregnancy rate. Four of 25 patients (16%) conceived while being monitored and undergoing treatment. Follicle growth, ovulation, and pregnancy rate were not significantly different as a function of parity, iatrogenic history (e.g., chemotherapy), age of disease onset, serum estradiol (E₂)/follicle stimulating hormone (FSH) level at the time of diagnosis, chromosomal abnormality, and positive autoantibody titer. The serum E₂ levels on days 1-5 of withdrawal bleeding (Day 1-5 E₂) were significantly higher in the cycles with successful follicle growth and ovulation than unsuccessful cycles (P < 0.05). Receiver-operator characteristic curve analysis revealed the cutoff value of the Day 1-5 E₂ to be 15.5 pg/mL, and an area under the curve (AUC) value of 0.674 for follicle growth and 0.752 for ovulation. The results suggest that cycles with a Day 1-5 E₂ ≥ 15.5 pg/mL have a higher rate of follicle growth and ovulation in patients with POI.