Objective To describe the variable disease expression and the patterns of development of major maternal morbidity and HELLP (haemolysis, elevated liver enzymes and low platelet count) syndrome in women with different subtypes of hypertensive disorders of pregnancy.
Design Prospective cohort study.
Setting Two university hospitals, tertiary care centres.
Population Two hundred and sixteen women participating in a randomised trial of temporising management in early-onset hypertensive disease (PETRA trial). Women were between 24 and 34 completed weeks and had either HELLP syndrome, severe pre-eclampsia, eclampsia or hypertension and fetal growth restriction. Women were delivered in the event of fetal marked heart rate abnormalities, pulmonary oedema, therapy-resistant hypertension or recurrent HELLP syndrome.
Methods Trial data were reanalysed to assess the time of onset of major maternal morbidity (e.g. pulmonary oedema, liver haematoma), HELLP syndrome and clinical disease. Associations between clinical parameters and prolongation of pregnancy were explored using logistic regression.
Main outcome measures Diagnosis from admittance to discharge, major maternal morbidity and prolongation of pregnancy.
Results The median time to delivery or fetal death was 8.2 (range 0.1–44) days. At study entry, 56 women (26%) had more than one diagnosis; this increased to 171 women (79%) by the time of discharge. The incidence of major maternal morbidity (total 26) was 4.2% at 2–4 days after inclusion and a mean of 1.7% (range 0–2%) thereafter per time frame of 3 days. The mean incidence of new or recurrent HELLP syndrome episodes was 5.5% (range 1.9–8.7%) per time frame of 3 days during the first 3 weeks after inclusion.
Conclusions Pre-eclampsia is a dynamic disease, with extensive overlap of subtypes of the syndrome. Prolongation of pregnancy in early-onset hypertensive disorders results in the development of further HELLP syndrome episodes and reversible major maternal morbidity but may improve perinatal healthy survival.