Keele Research Repository

Hypertensive disorders of pregnancy (HDP) are a major cause of maternal morbidity. However, short-term outcomes of HDP subgroups remain unknown. Using National Inpatient Sample database, all delivery hospitalizations between 2004 and 2014 with or without HDP (preeclampsia/eclampsia, chronic hypertension, superimposed preeclampsia on chronic hypertension, and gestational hypertension) were analyzed to examine the association between HDP and adverse in-hospital outcomes. We identified >44 million delivery hospitalizations, within which the prevalence of HDP increased from 8% to 11% over a decade with increasing comorbidity burden. Women with chronic hypertension have higher risks of myocardial infarction, peripartum cardiomyopathy, arrhythmia, and stillbirth compared to women with preeclampsia. Out of all HDP subgroups, the superimposed preeclampsia population had the highest risk of stroke (odds ratio [OR] 7.83, 95% confidence interval [CI] 6.25 to 9.80), myocardial infarction (OR 5.20, 95% CI 3.11 to 8.69), peripartum cardiomyopathy (OR 4.37, 95% CI 3.64 to 5.26), preterm birth (OR 4.65, 95% CI 4.48 to 4.83), placental abruption (OR 2.22, 95% CI 2.09 to 2.36), and stillbirth (OR 1.78, 95% CI 1.66 to 1.92) compared to women without HDP. In conclusion, we are the first to evaluate chronic systemic hypertension without superimposed preeclampsia as a distinct subgroup in HDP and show that women with chronic systemic hypertension are at even higher risk of some adverse outcomes compared to women with preeclampsia. In conclusion, the chronic hypertension population, with and without superimposed preeclampsia, is a particularly high-risk group and may benefit from increased antenatal surveillance and the use of a prognostic risk assessment model incorporating HDP to stratify intrapartum care.