Ultrasonic and endocrinologic relationships in spontaneous and induced follicular phase

To correlate ovarian growth and follicular size with 17/ß-estradiol (E2) and androstenedione (A) peripheral levels, 20 induced cycles, 6 spontaneous ovulatory cycles and 6 spontaneous anovulatory cycles from 32 women during follicular phase were examined in order to obtain a better insight in the events involved in multiple folliculogenesis. In spontaneous ovulatory cycles, a significant correlation was obtained between E2 plasma levels and volume of the dominant follicle (p< 0.05) as well as total follicular volume (p < 0.01). Plasma A was significantly related with sonographic features likely related to ovarian stroma as well as preantral and antral subordinated follicles, which usually fail to ovulate. Significant correlation between E2/A peripheral ratio and volume of the dominant follicle(s) was also found (p < 0.01). In anovulatory cycles, inverse significant correlation between E2 and sonographic aspects of degenerating antral follicles (p< 0.001 ) was found, whereas a positive significant correlation between E2 and ovarian stroma was obtained (p<0.001 ). No correlation between peripheral A and any ovarian sonographic compartment was evident. However in the anovulatory cycles group a significant correlation between A v E2 peripheral levels was found, too. During HMG regimen, all the ovarian compartments seemed to be responsible for E2 peripheral levels. Ovarian stroma as well as preantral and multiple antral follicles were related to A levels. E2/A peripheral ratio did not result to be a good indicator of the large follicles. During “pure” FSH therapy, exclusive correlations between estrogen and large follicles as well as total follicular volume were found. Significant correlation between A and ovarian stroma as well as subordinated antral follicles were obtained. E2/A ratio resulted to be a good indicator of the number of the large follicles. The findings of the present investigation indicate that in spontaneous and induced cycles, endocrine events associated to follicular development are quite different, depending on therapeutic regimen. A more normal follicular maturation may result from FSH regimen in comparison to HMG. Implications of the results in clinical monitoring of gonadotropin therapy may be evaluated in the future.