Objectives: To characterize hemodynamics of human ovarian follicles in the course of their development and to compare the results in relation to the age of patients, pregnancy, location of the ovary, and the quality of the oocytes.
Design: Serial measurements of peak velocity and resistance index by color Doppler imaging.
Setting: The In Vitro Fertilization Clinic, Success Through Assisted Reproductive Technologies, Inc., Toronto, Ontario, Canada.
Patients: Fifty-two women undergoing hormonal stimulation for IVF.
Main outcome measures: The perifollicular peak velocity and resistance index values.
Results: The perifollicular peak velocity values were gradually increasing with the increasing size of the follicles. Highly significant elevation of the peak velocity was observed especially after hCG injection. Such rapid rise of blood velocity was greater in the right ovary than in the left in the younger patients (mean age, 34 years) whereas in older patients (mean age, 41 years), the greater values were observed in the left ovary. There was no significant difference in peak velocity or resistance index between pregnant and nonpregnant patients.
Conclusions: There is a strong, positive correlation between the size of ovarian follicles and their peak velocity, which suggests an increase of blood flow around developing follicles in the course of the follicular phase. Human chorionic gonadotropin plays an important role in inducing influx of blood within follicles; however, the significance of this event remains obscure. It appears that the resistance index is not a useful parameter for characterization of the intrafollicular flow. Changes in peak velocity did not correlate with oocyte quality and may have no predictive value for IVF outcome.