Does pelvic congestion syndrome cause recurrent miscarriage?

Does Pelvic Congestion Syndrome Cause Miscarriages?

No, there is no established causal relationship between pelvic congestion syndrome (PCS) and recurrent miscarriage based on current evidence.

The Evidence

The provided guidelines and research do not demonstrate any link between PCS and miscarriage risk. Here's what we know:

What Causes Recurrent Miscarriage

According to the 2023 RCOG guideline on recurrent miscarriage 1, the established causes include:

• Genetic factors: Chromosomal abnormalities (up to 60% of sporadic miscarriages)
• Acquired thrombophilia: Particularly antiphospholipid syndrome
• Anatomical factors: Uterine anomalies (affecting up to 38% of women with recurrent miscarriage)
• Endocrine factors: Thyroid dysfunction
• Inherited thrombophilias: Weak association only

Pelvic congestion syndrome is not mentioned as a cause of recurrent miscarriage in any major guideline 2, 1.

What PCS Actually Causes

PCS is characterized by 3, 4, 5:

• Chronic pelvic pain (dull, aching, worsened by standing)
• Post-coital pain
• Dyspareunia
• Vulvar varices
• Pain exacerbation during premenstrual period

The Infertility Question

One small study 6 reported that 8 of 12 women (66.7%) achieved pregnancy after ovarian vein embolization for PCS when it was "suspected to be the only cause of infertility." However:

• This was a tiny retrospective case series (12 patients)
• The mechanism linking PCS to infertility remains unproven
• Infertility is not the same as miscarriage
• No data exist linking PCS to pregnancy loss

What the Guidelines Say About Recurrent Miscarriage Risk Factors

The 2024 BJOG guideline 2 specifically addresses recurrent miscarriage and notes:

• Evidence is conflicting and comes from retrospective studies
• The largest study showed no increased risk of small-for-gestational-age babies (aOR 1.07,95% CI 0.93–1.23)
• Some women with unexplained recurrent miscarriage may have underlying abnormal placentation, but this relates to placental dysfunction, not pelvic venous congestion

Clinical Bottom Line

If you have a patient with both PCS and recurrent miscarriage, these are two separate conditions requiring independent evaluation and management:

1. For recurrent miscarriage 1:

   • Test for antiphospholipid syndrome (lupus anticoagulant, anticardiolipin antibodies)
   • Cytogenetic analysis of pregnancy tissue
   • Assess for uterine anomalies with 3D ultrasound
   • Check thyroid function and TPO antibodies
   • Parental karyotyping if indicated

2. For PCS 3, 4:

   • Diagnose with transvaginal ultrasound (ovarian vein >7-8 mm, flow velocity <3 cm/s)
   • Consider venography with IVUS if intervention planned
   • Treat with ovarian vein embolization if symptomatic

Do not attribute miscarriages to PCS, and do not expect treatment of PCS to prevent future pregnancy losses. The pathophysiology of venous congestion in the pelvis has no established mechanism for causing embryonic or fetal demise.