Dissertation
Effects of pregnancy and preeclampsia on maternal vascular and brain function
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2023
DOI: 10.25820/etd.007235
Abstract
Preeclampsia is a cardiovascular complication of pregnancy affecting 3-6% of pregnancies in the United States and is increasingly recognized as an important risk factor for early cardiovascular and cerebrovascular disease and dementia later in life. Preeclampsia is characterized by a significant latent period wherein cardiovascular dysregulation is observed in very early gestation while clinical manifestation occurs >20 weeks. Given preventative measures are limited and incidence is rising, there is a growing need to understand early pregnancy cardiovascular markers of preeclampsia and feasible, modifiable mitigating factors. In this regard, the focus of Chapter 3 is to first evaluate the degree to which elevated large artery stiffness (i.e., aortic stiffness), augmented blood pressure variability and blunted baroreflex sensitivity in early pregnancy are associated with the development preeclampsia and mechanistically linked. The second focus of Chapter 3 is to determine whether habitual physical activity and sedentary behavior in early pregnancy are related to these markers of cardiovascular and autonomic function. Our results demonstrate that blood pressure variability in early pregnancy is elevated in those who develop preeclampsia and related to higher aortic stiffness. Further, excessive sedentary time in the first trimester may contribute to elevated blood pressure variability while light-intensity physical activity may mitigate this effect as gestation advances.
Women experience reductions in memory, processing speed and concentration during pregnancy, which is particularly pronounced in early-mid gestation. Despite this common experience and confirmation with objective cognitive testing, few studies have sought to understand contributing factors or interventional targets. Therefore, the focus of Chapter 4 is to compare cognitive performance in the first trimester of pregnancy with that of non-pregnant controls and assess the degree to which mood, stress, pregnancy-specific symptoms (e.g., nausea), and habitual activity cycles (physical activity, sedentary behavior, sleep) are related to lower cognitive performance. Our results suggest that memory performance is selectively reduced in the first trimester relative to non-pregnant performance, independent of education. A greater burden of pregnancy symptoms and reduction in pregnancy-specific health-related quality of life was associated with lower memory performance, while sleep duration and physical activity were positively related to memory and executive function, identifying these behaviors as potential interventional targets.
Long-term adverse impacts of preeclampsia on maternal cardiovascular health are well established, but mechanisms by which women with a history of preeclampsia are at risk of early cognitive aging and approaches to allay this progression have not been characterized. In Chapter 5, the effect of preeclampsia on cardiovascular function and hemodynamics (aortic stiffness, twenty-four-hour blood pressure and variability), cerebrovascular blood flow, cerebral microstructure and cognitive performance was investigated. Preliminary findings demonstrated that women with a history of preeclampsia exhibit lower cognitive performance and a pronounced association between augmented blood pressure variability and lower cognitive performance, which may be related in part to the adverse effect of blood pressure variability on cerebral microstructure. Additionally, cerebrovascular resistance was elevated after preeclampsia and related to reduced cerebral microstructure. Finally, in Chapter 6, results showed that at-home blood pressure monitoring 1-4 years after pregnancy was effective in screening for hypertension, a risk factor for later cardiovascular disease and cognitive aging, in relation to the less well-tolerated twenty-four-hour ambulatory monitoring. Habitual activity behaviors were assessed in relation to postpartum hypertension and aortic stiffness. Findings indicate that postpartum sedentary time is associated with higher aortic stiffness, while light physical activity is associated with lower aortic stiffness. In addition, sleep quality was beneficially related to twenty-four-hour blood pressure patterns. Altogether, this work characterizes cardiovascular function in early pregnancy prior to the development of preeclampsia, factors related to cognitive function in pregnancy and postpartum after preeclampsia and informs potential behavioral interventional approaches to promote cardiovascular and brain health during pregnancy and after preeclampsia.
Details
- Title: Subtitle
- Effects of pregnancy and preeclampsia on maternal vascular and brain function
- Creators
- Virginia Nuckols
- Contributors
- Gary Pierce (Advisor)Kara Whitaker (Committee Member)Mark Santillan (Committee Member)Anna Stanhewicz (Committee Member)Karin Hoth (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Health and Human Physiology
- Date degree season
- Spring 2023
- DOI
- 10.25820/etd.007235
- Publisher
- University of Iowa
- Number of pages
- xvii, 348 pages
- Copyright
- Copyright 2023 Virginia Nuckols
- Language
- English
- Date submitted
- 04/25/2023
- Date approved
- 06/30/2023
- Description illustrations
- illustrations
- Description bibliographic
- Includes bibliographical references (pages 292-348).
- Public Abstract (ETD)
Preeclampsia is a pregnancy complication defined by high blood pressure and organ dysfunction that contributes to short- and long-term poor outcomes for mother and infant, including elevated risk for cardiovascular disease and cognitive impairment. Mechanisms leading to preeclampsia and long-term poor maternal outcomes are not well understood and possible methods to prevent preeclampsia and long-term risk are not established. The overall focus of this dissertation is to evaluate cardiovascular and brain health during and after a pregnancy affected by preeclampsia and the influence of habitual activity, such as physical activity, sedentary behavior, and sleep on these outcomes. Cardiovascular adaptations to pregnancy are attenuated in women with a history of preeclampsia. This work studied early pregnancy cardiovascular function and the degree to which this was associated with physical activity (Chapter 3). Women report reductions in cognitive performance during pregnancy, thus this work additionally evaluated determinants of cognitive performance in pregnancy (Chapter 4). Finally, women with a history of preeclampsia exhibit sustained hypertension and vascular dysfunction of the large central arteries, but whether this contributes to premature brain aging is not established. Therefore, this work further investigated links between postpartum cardiovascular health and brain health after preeclampsia (Chapter 5) and lifestyle approaches to detect and mitigate risk of postpartum hypertension (Chapter 6).
- Academic Unit
- Health and Human Physiology
- Record Identifier
- 9984428939302771
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