Last but not least, compression from the appropriate common iliac artery about the left frequent iliac vein towards the spine and pelvic brim is thought to cause iliofemoral deep venous thrombosis (Could–Thurner syndrome) along with the pelvic varices of PCS. This might weaken the vein wall bringing about dilatation. Estrogen https://sgvasculargrp.com/medical-condition/pelvic-congestion-syndrome/