Intraovarian blood flow measured with color doppler ultrasonography inversely correlates with vascular density in the human corpus luteum of the menstrual cycle

OBJECTIVE: To evaluate the morphologic characteristics underlying the ultrasonographic appearance and blood flow dynamics in the human corpus luteum (CL) of the menstrual cycle. DESIGN: Cross-sectional study. SETTING: Ume? University Hospital, Ume?, Sweden. PATIENT(S): Twenty-six otherwise healthy women with proven fertility and a history of regular menstrual cycles, scheduled for elective hysterectomy or tubal sterilization. INTERVENTION(S): An ovulatory LH rise in urine was established and the CL age was determined according to the day after the LH rise. Before surgery, a standardized ultrasonographic examination of the CL, including B-mode and color Doppler ultrasonography measurements, was performed. Upon commencing the minilaparotomy, the CL was excised and measured using a digital slide-caliper. The volume density (percentage of CL volume occupied by blood vessels) of factor VIII-related antigen immunostained endothelial cells was determined. MAIN OUTCOME MEASURE(S): Pulsatility index obtained from intraovarian blood vessels supplying the CL and volume density of blood vessels in CL tissue. The CL maximal and minimal outer and inner dimensions were measured in vivo by ultrasonography and ex vivo by a digital slide caliper. RESULT(S): A statistically significant decrease of blood vessel density and an increased resistance to blood flow, as indicated by pulsatility index, was established during the course of corpus luteum development. An inverse correlation between pulsatility index and volume density of blood vessels was found. A high degree of agreement between ultrasonographic and anatomic measurements of surgically removed CL was found. CONCLUSION(S): Transvaginal ultrasonography in combination with intraovarian color Doppler flow measurements is a simple and reliable method to evaluate the size and vascularization of the human CL.