The Clinical Spectrum of Preeclampsia

Preeclampsia is much more than hypertension and proteinuria—it is a syndrome affecting virtually every organ system. The concept that preeclampsia is a protean syndrome is important. Like other syndromes, in individual patients, some organ systems are predominantly affected more than others. Preeclampsia, characterized by hypertension, proteinuria, edema, and overt or subclinical coagulation and liver function abnormalities, occurs more commonly in nulliparas, usually after 20 weeks' gestation, and most often near term. There is a deceptively benign form of preeclampsia whose initially mild clinical presentation may be misleading. The woman presents with borderline thrombocytopenia, and perhaps slightly abnormal serum transaminase levels, normal or minimally elevated blood pressure, and a little or no renal dysfunction. But these seemingly mild complications may rapidly become life threatening when within 24–48 hours there is progression to a syndrome characterized by hemolysis with marked evidence of both liver and coagulation abnormalities that include serum transaminase and lactic dehydrogenase increasing to >1000 U/L, platelet counts decreasing to <40,000/mL, with schizocytes seen on the blood smear. This complication is termed the “HELLP syndrome”—acronym for hemolysis, elevated liver enzymes, and low platelets—and constitutes an emergency requiring termination of the pregnancy.