Pelvic congestion syndrome is a cause of chronic pelvic pain in women, produced by enlarged, dilated, and incompetent veins within the pelvis. Similar to varicose veins in the legs, these pelvic veins become engorged when their valves fail to close properly, causing blood to reflux and pool rather than returning to the heart. The resulting venous hypertension generates a characteristic dull, aching pelvic pain that worsens throughout the day.
Pelvic congestion syndrome is one of the most underdiagnosed causes of chronic pelvic pain because it produces no abnormality on laparoscopy — the conventional tool for pelvic pain investigation — and its symptoms overlap extensively with those of endometriosis, adenomyosis, and uterine fibroids. Unlike these conditions, pelvic congestion syndrome is a vascular diagnosis that requires dedicated vascular imaging rather than tissue sampling. MRI with magnetic resonance venography (MRV) can identify dilated ovarian and pelvic veins while simultaneously excluding these other structural causes of chronic pelvic pain — making it uniquely efficient in the workup of a patient with unexplained pelvic pain and a negative laparoscopy.
Causes
Ovarian and pelvic vein insufficiency.
The fundamental problem is incompetence of the valves within the ovarian veins, internal iliac veins, or their tributaries. Normally, valves within these veins prevent retrograde blood flow, directing venous return toward the heart. When these valves become incompetent — failing to close against the hydrostatic pressure of the blood column above them — blood refluxes backward and accumulates in the pelvic venous plexuses surrounding the ovaries, broad ligaments, and uterus. Progressive distension of these veins beyond 5–6 mm in diameter is the diagnostic threshold, and the resulting venous hypertension causes the chronic pain, congestion, and soft tissue changes that characterize the syndrome. The ovarian veins are uniquely vulnerable because they lack the secondary venous drainage pathways present in the legs — when reflux occurs, the entire ovarian venous plexus bears the pressure load.
Other contributing factors.
Multiple pregnancies are the single greatest risk factor — during each pregnancy, the ovarian veins must accommodate up to a 60-fold increase in blood flow to the gravid uterus, causing permanent dilation and valve damage that does not fully reverse after delivery. Estrogen contributes by promoting venous wall relaxation and dilation — women taking estrogen-containing contraceptives or hormone replacement may experience worsening symptoms. Specific anatomic compression syndromes can precipitate or worsen pelvic venous congestion: nutcracker syndrome — compression of the left renal vein between the superior mesenteric artery and the aorta — causes elevated pressure in the left renal vein that is transmitted retrograde into the left ovarian vein, producing left-sided pelvic congestion; May-Thurner syndrome — compression of the left common iliac vein by the overlying right common iliac artery — causes left-sided pelvic venous hypertension by obstructing outflow. Recognizing these underlying anatomic causes is critical because their treatment differs from simple ovarian vein embolization.
Symptoms
The hallmark of pelvic congestion syndrome is chronic pelvic pain lasting more than 6 months — typically described as a dull, heavy, or aching sensation in the lower abdomen and pelvis rather than sharp or colicky. The characteristic temporal pattern is the key diagnostic clue: pain that worsens progressively throughout the day with upright posture (increased hydrostatic pressure in standing dilates the incompetent veins further), worsens after prolonged standing, and is reliably relieved by lying down — a pattern not seen with endometriosis or fibroids. Pain characteristically worsens around menstruation, after intercourse (postcoital ache lasting hours), and with physical exertion or lifting. Additional symptoms include dyspareunia, low back pain, vulvar or buttock varicosities (visible dilated veins at the vulva, perineum, or upper thighs — present in approximately 30% of cases and highly specific when identified), heaviness in the vaginal area, urinary urgency, and irregular or heavy menstrual bleeding. The symptom burden is often dismissed or attributed to anxiety or musculoskeletal causes because laparoscopy — performed under general anesthesia with the patient supine — decompresses the pelvic veins and reveals no abnormality, producing a false-negative result that perpetuates the diagnostic delay.
Diagnosis
Clinical diagnosis requires a high index of suspicion, particularly in multiparous women of reproductive age with chronic pelvic pain that is characteristically worse with standing and relieved by recumbency, in whom laparoscopy has been unrevealing. Pelvic ultrasound with Doppler can demonstrate dilated ovarian veins (greater than 6 mm) and reversed flow, but is operator-dependent and limited in its ability to evaluate the full course of the ovarian veins and the retroperitoneum.
An MRI of the pelvis with magnetic resonance venography (MRV) is the optimal noninvasive diagnostic study. MRI demonstrates dilated, tortuous ovarian and pelvic veins as serpiginous T2-hyperintense tubular structures surrounding the ovaries and broad ligaments, identifies the extent of venous involvement, and — critically — evaluates the retroperitoneum for anatomic compression at the level of the left renal vein (nutcracker) or left common iliac vein (May-Thurner). Time-resolved MR angiography can demonstrate dynamic venous reflux. MRI simultaneously excludes endometriosis, adenomyosis, fibroids, and ovarian pathology — providing the comprehensive pelvic assessment that a purely vascular study cannot. Catheter-directed pelvic venography performed by an interventional radiologist remains the gold standard — demonstrating ovarian vein diameter, reflux, and the distribution of pelvic varices — and is typically performed at the time of embolization treatment, combining diagnosis and therapy in a single procedure.
Classification
Pelvic venous disease is classified by the anatomic source of venous insufficiency and its underlying mechanism.
- Primary ovarian vein reflux: Incompetent ovarian vein valves without an identifiable obstructing cause. The most common pattern, more often left-sided due to the longer course and more acute angle of the left ovarian vein as it drains into the left renal vein.
- Internal iliac vein reflux: Incompetent valves in the internal iliac vein and its uterine and vaginal tributaries. Often bilateral and associated with significant vulvar varicosities.
- Nutcracker syndrome-related: Left renal vein compression between the aorta and superior mesenteric artery causes elevated renal vein pressure transmitted retrograde through the left ovarian vein into the pelvic venous plexus. May also cause hematuria and left flank pain from renal venous hypertension.
- May-Thurner syndrome-related: Compression of the left common iliac vein by the right common iliac artery obstructs pelvic venous outflow and causes left-sided pelvic venous hypertension. Also a risk factor for left-sided deep vein thrombosis.
Treatments
Treatment is tailored to symptom severity, the specific venous anatomy identified on imaging, the presence of underlying compression syndromes, and the patient's reproductive plans.
Conservative care: Non-steroidal anti-inflammatory medications for pain management, compression shorts or pelvic support garments to reduce venous pooling in upright posture, and activity modification are appropriate for mild symptoms. Progestin therapy (medroxyprogesterone acetate) and GnRH agonists reduce estrogen-driven venous dilation and can provide meaningful symptom relief while formal treatment is planned, though symptoms typically return after discontinuation.
Pelvic vein embolization.
Transcatheter ovarian vein embolization is the most effective and widely performed treatment for pelvic congestion syndrome. An interventional radiologist accesses the ovarian veins via a femoral or jugular venous approach, performs venography to map the refluxing veins and pelvic varices, and deploys metallic coils and/or sclerosant foam to permanently occlude the incompetent veins. Both ovarian veins are typically treated even when symptoms are primarily unilateral, because bilateral incompetence is common and contralateral reflux frequently develops if only one side is treated. Internal iliac vein branches contributing to pelvic varices are embolized at the same time. The procedure is performed as an outpatient under light sedation, typically takes 45–90 minutes, and has demonstrated significant pain reduction in 70–85% of patients in published series. Recovery is rapid — most patients return to normal activities within 1–2 weeks.
Treatment of underlying compression syndromes.
When nutcracker syndrome with significant left renal vein compression is identified, endovascular stenting of the left renal vein or surgical transposition of the superior mesenteric artery may be required to relieve the underlying pressure gradient before or alongside embolization. May-Thurner syndrome with symptomatic left iliac vein compression is typically treated with venous stenting of the compressed iliac segment, which restores normal pelvic venous outflow and reduces the pressure driving pelvic varicosity formation.
Surgery.
Surgical ligation of the ovarian veins — historically performed laparoscopically or via open approach — is now rarely needed given the effectiveness and lower morbidity of embolization. Hysterectomy with bilateral salpingo-oophorectomy was once offered for refractory cases but is an extreme measure that does not reliably address the underlying venous insufficiency and carries the risks of surgical menopause — it is not a recommended primary treatment for pelvic congestion syndrome.
Get an MRI to Confirm Your Diagnosis
Before surgical planning or starting treatment, a clear MRI diagnosis ensures the right path forward. First Look MRI offers self-pay Pelvis MRI scans — no doctor's order or insurance required — at our locations in Georgia, Texas, and Colorado.