OBJECTIVE To test the null hypothesis that the course and outcome of pregnancy in patients with severe pre-eclampsia receiving temporising haemodynamic treatment does not depend on the presence or absence of the syndrome of haemolysis, elevated liver enzymes, and a low platelet count (HELLP). METHODS A case-controlled study. METHODS High risk obstetric unit, University Hospital Rotterdam-Dijkzigt, Rotterdam. METHODS One hundred and twenty-eight consecutive pre-eclamptic patients with HELLP, gestational age less than 34 weeks, matched for maternal and gestational age with 128 pre-eclamptic patients without HELLP. METHODS Both groups were treated with volume expansion and pharmacologic vasodilatation under invasive haemodynamic monitoring with the aim of prolonging gestation and enhancing fetal maturity. METHODS Maternal and perinatal outcome in patients with and without HELLP. RESULTS Except for variables pertaining to HELLP, clinical and laboratory data and median prolongation of pregnancy did not differ between both groups. Complete reversal of HELLP occurred in 43% of patients. Perinatal mortality was 14.1% in HELLP patients and 14.8% in patients without HELLP. No maternal complications occurred. CONCLUSIONS We cannot reject the null hypothesis. Our data do not support a general recommendation of prompt termination of pregnancy in HELLP. Temporising treatment may improve fetal and neonatal as well as maternal outcome.