Comparing severity of different subtypes of preeclampsia using different diagnostic criteria - a retrospective cohort study

Comparing Severity of Different Subtypes of Preeclampsia Using Different Diagnostic Criteria - A Retrospective Cohort Study. BACKGROUND: New diagnostic criteria introduced by ISSHP in 2018 and ACOG in 2020 lowered diagnostic thresholds to create distinct subtypes. OBJECTIVES: We assess changes in prevalence and compare biochemical profiles and outcomes of patients diagnosed by different criteria. We evaluated associations of each diagnostic component with adverse outcomes. STUDY DESIGN: Singleton pregnancies with any hypertensive disorder in pregnancy diagnosed between 1/1/2011 and 31/12/2019 had demographics and outcomes retrieved from an electronic records system. Patients were reclassified by ISSHP 2001, ACOG 2020, and ISSHP 2018 criteria. Additional patients identified were analysed separately. MAIN OUTCOME MEASURES: Prevalence and associations between categorical variables and adverse outcomes were calculated. Multivariate logistic regression between components of each criteria and adverse outcomes was performed. RESULTS: Prevalence increased by 4.0-21.6% from 1.99% to 2.07-2.42% (ACOG 2020, ISSHP 2018 respectively). Additional patients diagnosed by ISSHP 2018 and ACOG 2020 had less severe hypertension (0.7% and 0.0% vs 15.6%, p < 0.001), MgSO4 use (0.0% vs 8.6%, p < 0.05), preterm birth <37 weeks (8.5% and 4.0% vs 35.7%, p < 0.001), Caesarean section (36.2% and 12.0% vs 56%, p < 0.001) and NICU admission >24 h (2.8 and 8.0% vs 10.1%, p < 0.001 and not significant) than patients diagnosed by ISSHP 2001. Proteinuria, thrombocytopenia, elevated creatinine and transaminases were significantly associated with adverse outcomes across most groups. CONCLUSION: Using newer diagnostic criteria increases incidence. Additional patients had milder disease and better outcomes despite management as gestational hypertension.