The uterine venous plexus is a complex set of interconnected blood vessels. Two uterine veins arise from the side of the uterus, where they also connect with the vaginal and ovarian plexuses. The two uterine veins drain into the internal iliac vein. The plexus is also structurally connected to the superior rectal vein. The veins in the plexus work by transporting deoxygenated blood from the uterus, and carry it back to the heart. Being a highly vascular organ, the uterus needs a functional set of blood vessels to keep the uterine tissues and muscles nourished with oxygen and other substances, such as glucose and hormones. The veins in the plexus need to participate with the uterine arteries to promote adequate blood circulation that will help regulate normal uterine events, such as pregnancy, menstrual cycles and menopause. During labor, the uterine venous plexus plays a very critical role to maintain proper circulation. As the uterine muscles contract, it is highly important that the veins within the plexus function well enough to provide blood for the uterus.