Hemolysis, elevated liver enzymes and low platelet count, or HELLP syndrome, is a manifestation of pregnancy-induced hypertension. It is a multisystem, life-threatening disorder. Pregnant women with HELLP syndrome often require critical care nursing. Collaboration between the critical care nurse and the obstetric nurse is essential because it enhances the nursing management of the mother and her fetus. This article reviews selected physiologic changes in pregnancy and the pathophysiology of pregnancy-induced hypertension and HELLP syndrome. These changes and pathophysiology serve as the rationale for the nursing care guidelines.