How common is hellp syndrome?

HEELP syndrome. It is an infrequent form of severe preeclampsia consisting of hemolysis, elevated liver enzymes and low platelets. It is a high risk condition with possible severe complications.
Relatively rare. Hellp syndrome (hypertension, elevated liver enzymes, low platelets) occurs in 1-2/1000 pregnancies and in 10-20% of pregnancies complicated by preeclampsia/eclampsia. It is a form of severe preeclampsia.