(1037) Outcomes of superimposed preeclampsia compared with severe hypertension in pregnant patients with mild chronic hypertension

In women with chronic hypertension (cHTN), severe hypertension v. superimposed preeclampsia presents a diagnostic and management challenge. Our objective was to compare maternal and neonatal outcomes by type of hypertensive complication (worsening or severe hypertension only versus superimposed preeclampsia with and without severe features) in gravidae with mild cHTN.


Study Design:

Secondary analysis of a multicenter antihypertensive treatment trial for mild cHTN in pregnancy. Patients who developed severe hypertension ( ≥160/110 mmHg) only or preeclampsia with and without severe features prior to delivery were included. Preeclampsia was defined by ACOG criteria (severe hypertension alone did not suffice) and centrally adjudicated in the original trial. We excluded preeclampsia or severe hypertension prior to 20 weeks or postpartum. Primary outcome was a composite maternal outcome (placental abruption, pulmonary edema, ICU admission, renal failure, blood transfusion, & hospital readmission). Secondary outcomes included additional maternal and neonatal outcomes. The preeclampsia and severe cHTN groups were compared.


Results:

954 patients included: 59 with non-severe preeclampsia, 287 with severe hypertension only, and 608 with preeclampsia and severe features. Patients with severe HTN or severe pre-e were more likely to be black/non-hispanic and have pre-e history. Preeclampsia with severe features was associated with the highest frequency of the composite maternal outcome followed by severe hypertension and non-severe preeclampsia (14.3% vs 7.7% vs 0%, p= < 0.01); similar for ICU admission, transfusion, and hospital stay. Those with preeclampsia with severe features had the highest frequency of the composite perinatal outcome, preterm delivery < 37 weeks, NICU admission, NICU hospital days, birth weight < 2500 grams, and a lower mean GA at delivery (Table 2).


Conclusion:

Severe chronic hypertension alone was associated with a lower frequency of adverse pregnancy outcomes compared to preeclampsia with severe features, but a higher frequency compared to non-severe preeclampsia in patients with mild cHTN.