Objective: To examine pulsatility index (PI) and resistance index (RI) values in the uterine and arcuate arteries of patients with primary dysmenorrhea (PD) by color Doppler ultrasonography.
Study design: A total of 49 female university students were recruited for this prospective, observational study. The study group consisted of 25 nulliparous women with PD and a control group of 24 healthy, nulliparous women without dysmenorrhea. The women were examined using transabdominal color Doppler ultrasonography during the midluteal phase (days 18-22) and on the first day of the menstrual cycle. The mean PI and RI values for the right and left uterine arteries and arcuate artery were determined. Student's t test was used to compare the results between and within groups.
Results: The mean PI and RI values for the uterine and arcuate arteries in patients with PD were significantly higher on the first day of the menstrual cycle than in the midluteal phase (p < 0.001). Women with PD had significantly higher mean PI and RI values in all 3 arteries on the first day of the menstrual cycle than did the controls (p < 0.05). The Doppler index values of all 3 arteries during the midluteal phase were not significantly different between the groups.
Conclusion: There is increased impedance to blood flow within the uterus of women with PD on the first day of the menstrual cycle. This may be a sign of constriction of the uterine vessels and the cause of pain.