Association between diagnostic criteria of pre-eclampsia with severe features and adverse perinatal outcomes

Pre-eclampsia with severe features (PEC-SF) is a hypertensive disorder of pregnancy associated with significant maternal and perinatal morbidity. It is defined by heterogeneous criteria, including severe hypertension and signs of end-organ dysfunction. Whether individual criteria confer differential risk for adverse perinatal outcomes remains unclear. This gap limits clinicians' ability to risk stratify patients, guide management decisions, and provide individualized counseling regarding prognosis.

To estimate the association between individual diagnostic criteria in PEC-SF and adverse perinatal outcomes.

This is a retrospective cohort study of patients with PEC-SF who delivered at two academic medical centers from December 27, 2015 to December 30, 2017. Exposures included the number and type of severe criteria present at diagnosis. Our primary outcome was a composite of placental abruption, preterm birth <34 weeks, a small-for-gestational-age infant, or fetal demise. Secondary outcomes included preterm birth <37 weeks, delivery type, and <7 days of latency from diagnosis to delivery among those diagnosed at <33 weeks. A multivariable logistic regression model adjusted for maternal age, race, and pre-existing medical conditions estimated the adjusted odds ratios (aOR) and 95% confidence intervals (CIs) for the primary outcome.

There were 704 patients with PEC-SF. Of these, 608 (86.4%) had severe hypertension, 246 (34.9%) reported neurological symptoms, and 332 (47.2%) presented with ≥2 severe criteria. Of 704, 371 (52.7%) had a single criterion, most often severe hypertension (81.1%). The primary outcome was associated with severe hypertension (aOR: 1.36, 95% CI: 1.22, 1.52), thrombocytopenia (aOR: 1.28, 95% CI 1.13, 1.45), progressive renal insufficiency (aOR 1.16, 95% CI 1.03, 1.31), and impaired liver function (aOR: 1.15, 95% CI 1.04, 1.28). Unplanned cesarean delivery was associated with severe hypertension (aOR: 1.42, 95% CI: 1.02, 1.98) and impaired liver function (aOR: 1.13, 95% CI: 1.02, 1.25). The odds of the primary composite outcome increased with each additional criterion; among patients with severe hypertension, the odds of the primary outcome were significantly associated in those with two to three additional severe features (aOR: 1.47, 95% CI 1.30, 1.67).

Our findings demonstrate that not all severe features carry equal odds of adverse pregnancy outcome and highlight the importance of considering both the type and number of criteria when risk stratifying patients and guiding clinical management.