The natural history of HELLP syndrome: patterns of disease progression and regression.

Despite much recent interest in HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count), there is little published information about the natural history of this unique form of severe preeclampsia-eclampsia. The time course and pattern of laboratory abnormalities for 158 patients with HELLP syndrome managed in a single tertiary referral center between 1980 and 1989 were studied retrospectively. Despite considerable patient variation, most gravid women with HELLP syndrome had decreasing platelet counts until 24 to 48 hours after delivery. Conversely, lactate dehydrogenase concentrations usually peaked 24 to 48 hours post partum. In all patients who recovered, a platelet count greater than 1,000,000/mm3 was spontaneously achieved by the sixth postpartum day or within 72 hours of platelet nadir. An upward trend in platelet count and a downward trend in lactate dehydrogenase concentrations should be apparent in patients without complications by the fourth postpartum day. These data provide baseline information against which the course of individual patients can be compared and the infrequent, atypical case identified for interventive therapy.