Aggregated postpartum cerebral autoregulatory curves in normotensive individuals, preeclampsia with severe features, and superimposed preeclampsia with severe features

Objectives Impaired cerebral autoregulation could contribute to postpartum stroke risk in individuals with preeclampsia. We modeled aggregated static autoregulatory curves in the postpartum period in individuals with no hypertension, preeclampsia, and chronic hypertension with superimposed preeclampsia. Approach This is a retrospective analysis of data from a prospective observational study of postpartum participants. We measured continuous mean arterial pressure (MAP) with finger plethysmography and cerebral blood velocity (CBv) with transcranial Doppler within 2 weeks after delivery. Data were aggregated and group curves generated from normalized MAP and CBv data using 3rd order polynomial equations. We compared overall polynomial curve shapes between groups as well as pair-wise comparisons of autoregulatory range. Main Results A total of 73 participants were enrolled: 21 (29%) normotensive, 31 (42%) with preeclampsia and 21 (29%) with superimposed preeclampsia. Polynomial S-curves suggested a flatter plateau in the normotensive group compared with both preeclampsia groups, but the differences were not statistically significant. Autoregulatory range were wider in both preeclampsia groups than in the normotensive group, with a MAP range of 27.5 mmHg in the normotensive group, 43.2 mmHg in the preeclampsia group, and 31.5 mmHg in the superimposed preeclampsia group, but only the difference between the preeclampsia and normotensive groups reached statistical significance (p=0.02). Significance Static autoregulation curves generated using third-order polynomials showed distinct characteristics in postpartum participants with normotension, preeclampsia, and superimposed preeclampsia, and suggested a wider cerebral autoregulatory range in those with preeclampsia.