Incidence and risk factors for severe preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, and eclampsia at preterm and term gestation: a population-based study

The majority of previous studies on severe preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, and low platelet count syndrome were hospital-based or included a relatively small number of women. Large, population-based studies examining gestational age–specific incidence patterns and risk factors for these severe pregnancy complications are lacking. This study aimed to assess the gestational age–specific incidence rates and risk factors for severe preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, and eclampsia. We carried out a retrospective, population-based cohort study that included all women with a singleton hospital birth in Canada (excluding Quebec) from 2012 to 2016 (N=1,078,323). Data on the primary outcomes (ie, severe preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, and eclampsia) were obtained from delivery hospitalization records abstracted by the Canadian Institute for Health Information. A Cox regression was used to assess independent risk factors (eg, maternal age and chronic comorbidity) for each primary outcome and to assess differences in the effects at preterm vs term gestation (