3626: Predictability of transvaginal ultrasonography in terms of serum estradiol level per mature follicle in controlled ovarian hyperstimulation cycles using GnRH antagonists

Abstract

Objectives: Serum estradiol level on ovulation-triggering day during controlled ovarian hyperstimulation cycles using GnRH agonists (GnRHa) correlates well with number of mature ovarian follicles, and is approximately 150 to 250 pg/ml per follicle ≥ 14 mm in diameter. However, to date, few such reference data are available for GnRH antagonist (GnRHant) cycles. We attempted to evaluate a relationship between number of mature follicles and serum estradiol levels during GnRHant cycles.Methods: On ovulation-triggering day of GnRHant (n = 97) and GnRHa (n = 102) cycles, number of follicles ≥ 14 mm was counted using transvaginal ultrasonography, and serum estradiol level was measured using radioimmunoassay. Statistical correlation was analyzed between serum estradiol levels and number of mature follicles.Results: Clinical characteristics of study subjects did not differ between the two groups. Serum estradiol levels per follicle ≥ 14 mm were 201.9 pg/ml (r = 0.544, p < 0.001) in GnRHant cycles and 161.9 pg/ml (r = 0.357, p < 0.001) in GnRHa cycles, respectively.Conclusions: Estimated serum estradiol level per mature follicle of GnRHant cycles may be higher than that of GnRHa cycles, when measured by transvaginal ultrasound on ovulation-triggering day. We should interpret the relationship between number of mature follicles and serum estradiol level differently during GnRHant cycles. Objectives: Serum estradiol level on ovulation-triggering day during controlled ovarian hyperstimulation cycles using GnRH agonists (GnRHa) correlates well with number of mature ovarian follicles, and is approximately 150 to 250 pg/ml per follicle ≥ 14 mm in diameter. However, to date, few such reference data are available for GnRH antagonist (GnRHant) cycles. We attempted to evaluate a relationship between number of mature follicles and serum estradiol levels during GnRHant cycles. Methods: On ovulation-triggering day of GnRHant (n = 97) and GnRHa (n = 102) cycles, number of follicles ≥ 14 mm was counted using transvaginal ultrasonography, and serum estradiol level was measured using radioimmunoassay. Statistical correlation was analyzed between serum estradiol levels and number of mature follicles. Results: Clinical characteristics of study subjects did not differ between the two groups. Serum estradiol levels per follicle ≥ 14 mm were 201.9 pg/ml (r = 0.544, p < 0.001) in GnRHant cycles and 161.9 pg/ml (r = 0.357, p < 0.001) in GnRHa cycles, respectively. Conclusions: Estimated serum estradiol level per mature follicle of GnRHant cycles may be higher than that of GnRHa cycles, when measured by transvaginal ultrasound on ovulation-triggering day. We should interpret the relationship between number of mature follicles and serum estradiol level differently during GnRHant cycles.