Dynamic cerebral autoregulation in postpartum individuals with and without preeclampsia

Abstract

Background: Changes in dynamic cerebral autoregulation (DCA) may contribute to postpartum maternal cerebrovascular complications after preeclampsia. We hypothesized that DCA is impaired in the first week postpartum after diagnosis of preeclampsia with severe features (PSF), compared with normotensive postpartum individuals and healthy non-pregnant female volunteers.

Methods: We measured DCA within seven days after delivery in individuals with and without PSF, using transcranial Doppler and continuous arterial blood pressure monitoring with finger plethysmography. Historical data from 28 healthy female non-pregnant volunteers, collected using the same methods, were used for comparison. We used generalized harmonic wavelets to estimate autoregulation parameters (phase shift and gain) in very low frequency and low frequency bands, with lower phase shift and higher gain indicating impaired DCA function. We compared DCA parameters between the three groups using the Kruskal Wallis test.

Results: A total of 69 postpartum participants contributed data, of whom 49 had preeclampsia with severe features. Median phase shifts in both postpartum groups were higher compared with historical controls across all frequency ranges (p = 0.001), indicating faster autoregulatory response. Gain was higher in both postpartum groups than in historical controls across all frequency ranges (p = 0.04), indicating impaired dampening effect.

Conclusion: We found that postpartum individuals, regardless of preeclampsia diagnosis, had higher phase shifts and higher gain than healthy non-pregnant/postpartum female volunteers. Our results suggest hyperdynamic DCA with impaired dampening effect in the first week postpartum, regardless of preeclampsia diagnosis.

Keywords: Autoregulation; Cerebrovascular; Postpartum; Preeclampsia; Pregnancy.