Number and size of antral follicles as predictive factors in vitro fertilization and embryo transfer

Purpose: The purpose of the study was to evaluate whether number and size o f antral follicles can predict the outcome of in vitro fertilization-embryo transfer. Methods: A total of 113 patients were prospectively included into this stud y. After 19 days of down-regulation, number and size of follicles were dete rmined by using recent three-dimensional transvaginal ultrasound technology . Before application of gonadotropin, all follicles had been defined as ant ral follicles. According to size, antral follicles were categorized into So ur different groups: group I included antral follicles <5 mm, group II foll icles 5-10 mm; group III 11-20 mm; and group IV >20 mm. Pregnant and nonpre gnant patients were compared in terms of their number of antral follicles o f group I-IV. These four groups were then compared regarding implantation r ate, number of retrieved oocytes, endometriun thickness, and age. Results: Pregnant patients showed an significant higher number of follicles with the size between 5 and 10 mm (P = 0.04). A significant correlation wa s found between number of retrieved oocytes and antral follicle size of 5-1 0 mm (P = 0.0001). Antral follicles with a diameter between 5 and 10 mm dec reased significantly with age (P = 0.008). In groups III and IV, a signific ant correlation was Sound between antral follicle size (P = 0.016) and seru m estradiol level after gonadotropin-releasing hormone-agonist down-regulat ion (P = 0.011). Conclusions: We demonstrated that patients with a higher number of follicle s between 5 and 10 mm showed a significantly higher pregnancy rate, whereas patients with a dominant number of antral follicles > II mm have a higher cancellation rare due to ovarian low response.