HELLP is an acronym that refers to a syndrome characterized by Hemolysis with a microangiopathic blood smear, Elevated Liver enzymes, and a Low Platelet count . It probably represents a severe form of preeclampsia (table 1 and table 2), but the relationship between the two disorders remains controversial. As many as 15 to 20 percent of patients with HELLP syndrome do not have antecedent hypertension or proteinuria, leading some authorities to believe that HELLP is a separate disorder from preeclampsia [2-4]. Both severe preeclampsia and HELLP syndrome may be associated with serious hepatic manifestations, including infarction, hemorrhage, and rupture.
This topic will focus upon the clinical manifestations, diagnosis, and management of HELLP syndrome. Preeclampsia is reviewed in detail separately. (See "Preeclampsia: Clinical features and diagnosis" and "Preeclampsia: Management and prognosis".)
HELLP develops in approximately 0.1 to 0.8 percent of pregnancies overall and in 10 to 20 percent of women with severe preeclampsia/eclampsia.
A previous history of preeclampsia or HELLP is a risk factor for HELLP syndrome (see 'Recurrence in subsequent pregnancies' below). Sisters and offspring of women with a history of HELLP syndrome are also at increased risk of developing the syndrome . A variety of genetic variants associated with an increased risk of HELLP syndrome have been reported, but have no role in clinical management .
In contrast to preeclampsia, nulliparity is not a risk factor for HELLP syndrome . Half or more of affected patients are multiparous.