Supine hypotensive syndrome is characterized by hypotension (abnormally low blood pressure) and bradycardia (abnormally slow heartbeat) when a pregnant women (especially near term) lies down on her back. The clinical signs are relieved by placing the patient in the lateral position (on her side). This syndrome is the result of compression of the aorta and vena cava (major blood vessels) by the gravid uterus, thus obstructing the flow of blood circulation.