EDN1 and hypertension, pregnancy-induced: The possible mechanism for the increase of ET-1 is that there are endothelial cytotoxic factors that can cause vascular endothelial cell damage in patients with pregnancy-induced hypertension, release a large amount of ET-1 to promote vasoconstriction, and ischemia and hypoxia further aggravate endothelial cell damage, and then form a vicious circle (16).