Effect of pituitary down-regulation on the ovary before in vitro fertilization as measured using three-dimensional power Doppler ultrasound.

OBJECTIVE: To evaluate the changes taking place in the ovaries during pituitary down-regulation. DESIGN: Prospective observational study of women undergoing IVF treatment. SETTING: A tertiary referral center for assisted reproduction. PATIENT(S): Forty women who received the long buserelin acetate treatment protocol. Transvaginal three-dimensional power Doppler ultrasound examinations before and after pituitary down-regulation. INTERVENTION(S): Ovarian volume, number of follicles, vascularization index (VI), flow index (FI), vascularization flow index (VFI), and mean gray value (MG). RESULT(S): Before the pituitary down-regulation, the dominant ovary was larger in volume and had a lower MG than the nondominant ovary. After the down-regulation, there was a significant decrease in the volume and number of follicles and an increase in MG. After pituitary down-regulation, the dominant and nondominant ovaries did not differ from each other in any of the parameters. Polycystic ovaries were larger than normal ones before and after the down-regulation, without any differences in MG, VI, FI, or VFI. Right and left ovaries did not differ from each other after the down-regulation. CONCLUSION(S): The differences observed between dominant and nondominant ovaries seem to disappear after pituitary down-regulation. In addition, polycystic ovaries were always larger than the normal ones, but no differences could be detected in the stromal brightness or vascularity either before or after the administration of GnRH agonist therapy.