Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality. There is a lack of effective therapeutics for prevention or treatment. Our previous ex vivo work demonstrated that mitochondrial-antioxidants can reverse placental microvascular damage. Therefore, this study will evaluate whether MitoQ (Mitoquinol Mesylate, a mitochondrial-antioxidant) has the potential to restore vasodilation, improve placental function, and therefore promote pregnancy prolongation in patients with preeclampsia. This evaluation of clinical data, patient samples, and vascular function studies in patients with preeclampsia could translate into a viable therapeutic option.

Preeclampsia (PreE) impacts ~10% of pregnancies and has severe outcomes both during and after pregnancy. It is a leading cause of pregnancy-related deaths, and has long term cardiovascular consequences for maternal and child health. Despite advances in the understanding of preeclampsia over the past 50 years, the underlying unifying mechanism causing preeclampsia remains elusive. This critical gap not only encompasses lack of understanding of the pathophysiology, but it also includes a lack of therapeutics for prevention or treatment. Success in this study could translate into a clinical trial that could finally offer a treatment for PreE.

The investigators have recently demonstrated that endothelial function in the human placental microcirculation is impacted by excess reactive oxygen and nitrogen species (ROS, RNS) from the mitochondria (MT), which in preeclampsia, impairs vasodilation. Excess ROS causes decreased nitric oxide (NO) bioavailability, increased lipid peroxidation, uncoupled eNOS, peroxynitrite, and exacerbates MT dysfunction and MT DNA damage via alterations in NO. Microvascular function can be improved by mechanisms that rebalance the oxidative stress response. The investigators have shown that MitoTempol, a MT antioxidant, improves vasodilation. Moreover, the investigators have shown that a major part of the cycle of excessive oxidative stress is caused by MT DNA damage and subsequent activation of toll like receptor 9 (TLR9), and that inhibiting TLR9 prevents this dysfunction. The finding that MT antioxidants given ex-vivo can reverse placental vascular damage after delivery gives promise that treatment of patients during pregnancy could restore vasodilation and allow for safer prolongation of pregnancy.

MitoQ (Mitoquinol Mesylate) is a nutritional supplement, and mitochondrial antioxidant. MitoQ has been extensively studied pre- clinically in cell-culture, and pregnant mouse, rat, and sheep models of PreE or oxidative stress and demonstrated beneficial fetal results. It has been used in clinical trials for heart failure, hepatitis C, Parkinson's, and multiple sclerosis with doses from 10mg to 80mg per day.

Overall Hypothesis: The investigators hypothesize that MitoQ (Mitoquinol Mesylate)-treated preeclampsia patients will have improved brachial artery flow-mediated dilation (FMD) and laser Doppler flowmetry assessments of the cutaneous microvasculature, and that placental endothelial function in micro-vessels and placental pathology will be improved in treated patients. To demonstrate this, the investigators will enroll two pilot human cohorts- one of admitted patients with preeclampsia with severe features who will either continue standard in-patient clinical care or be supplemented daily with MitoQ (Mitoquinol Mesylate) and a second outpatient cohort of patients with preeclampsia without severe features who will received standard outpatient care or be supplemented daily with MitoQ

Aim: Test whether with MitoQ (Mitoquinol Mesylate) treatment in preeclamptic patients improves endothelial function Hypothesis: MitoQ (Mitoquinol Mesylate)-treated patients will have improved brachial artery FMD and laser Doppler flowmetry assessments of the cutaneous microvasculature and placental endothelial function in micro-vessels and placental pathology will be improved in treated patients.

Inclusion Criteria:

• Inpatient Cohort

  • pregnant patients with a clinical diagnosis of preeclampsia with severe features
  • gestational age between 23+0 and 32+0 weeks' gestation
  • singleton pregnancy
  • age 18-50 years old
  • No indication for immediate delivery (e.g. the patient and their physician team have planned expectant management of preeclampsia with severe features
  • Able to consent and follow a 2-step commend
  • English speaking

• Outpatient Cohort

  • Pregnant patients with a clinical diagnosis of preeclampsia without severe features
  • gestational age between 23+0 and 34+0 weeks' gestation
  • singleton pregnancy
  • age 18-50 years old
  • No indication for immediate delivery
  • Planned outpatient management of preeclampsia
  • Able to consent and follow a 2-step commend
  • English speaking

Exclusion Criteria:

• • Unable to stand from chair without physical assistance from another person (able to use assistive device).

  • History of blood clots in the extremities or any condition in which compression of the thigh or transient ischemia is contraindicated (i.e., wounds in the leg).
  • Chronic lasting symptoms (> 6 months) of severe COVID-19 (i.e., hospitalization)
  • History of head trauma or concussion within the past 6 months
  • Comorbid neurological disorder
  • Peripheral vascular disease
  • Diagnosed myocardial infarction or arrhythmia in the previous year
  • Resting SBP ≥180 mmHg or DBP ≥ 100 mmHg
  • Other significant medical condition likely to influence study or jeopardize safety as assessed by the Primary Investigator

Only patients who are pregnant are able to participate.

The cleaned, item-level spreadsheet data for all variables will be shared openly, along with example quantifications and transformations from initial raw data. Final files used to generate specific analyses as well as related results will also be shared. The rationale for sharing only cleaned data is to foster ease of data reuse. The final dataset will include clinical data procured from demographic and relevant medical record information from participants. We will share de-identified individual-participant level (IPD) data. Appropriate de-identification measures will be utilized from IRB approved protocols and informed consents.

Data will be made available 2 years after the completion of the study.

Those interested in accessing the data will contact the PI and the study team will review requests and share relevant de-identified individual-participant level (IPD) data .