Pelvic pain and venous congestion revisited: examining relationship between chronic pelvic pain and uterine venous size and blood flow.

OBJECTIVE:To investigate the relationship between increased uterine venous plexus diameter and chronic pelvic pain in women attending a gynecology clinic. METHODS:This was a retrospective study of patients attending a tertiary university hospital in London, UK. Women presenting to the gynecology clinic undergoing transvaginal ultrasound examination were recruited into the study. The largest trunk of the uterine venous plexus was measured on each side. Blood flow within the uterine veins was categorized into continuous or interrupted flow and evaluated using color and spectral Doppler ultrasound during normal respiration and on Valsalva maneuver to demonstrate the presence of venous reflux. The largest uterine vein diameter and its blood flow were used for the analysis. The main variables of interest were chronic pelvic pain, uterine vein diameter and type of blood flow. RESULTS:We included 1500 women in the study, of whom 584 (38.9% (95% CI, 36.5-41.5%)) reported chronic pelvic pain. Dysmenorrhea was the most common type of pelvic pain. Age (P < 0.001), menopausal status (P = 0.02), varicose veins (P = 0.01), adenomyosis (P < 0.001) and endometriosis (P < 0.001) were found to be independently associated with the occurrence of pain on multiple logistic regression analysis. There was no difference in uterine vein diameter between women with and those without pain (P = 0.10). Neither uterine vein diameter (P = 0.47) nor type of blood flow (P = 0.07) was significantly associated with the occurrence of pelvic pain on multiple logistic regression. CONCLUSIONS:Our findings show that uterine vein diameter is not associated with pelvic pain. However, we found other important clinical and demographic factors that are associated with chronic pelvic pain. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.