Acute Beetroot Juice Supplementation in Pre-eclampsia Pregnancies

The study will include women diagnosed with early-onset preeclampsia and a healthy pregnancy, in accordance with the guidelines of the American College of Obstetricians and Gynecologists. Participants will be required to sign informed consent forms following a detailed explanation of the study. Four groups will be formed, with twenty-four pregnant women randomly assigned to each group using a free online program. In each group (early-onset preeclampsia), twenty-four pregnant women will receive nitrate-enriched beet juice (Beet It®, James White, UK), while another twenty-four pregnant women will receive an equivalent amount of placebo juice. Additionally, the same division applies to the group of healthy pregnant women, with six healthy pregnant women receiving the nitrate-enriched beet juice and six healthy pregnant women receiving the placebo. The study will begin in the morning, between 7:30 a.m. and 8:30 a.m., following a standardized, low-nitrate breakfast provided by the hospital. Participants will be instructed to avoid nitrate-rich foods the night before and will receive guidance from the project team and the hospital's nutrition service. The hospital's nutrition team will supervise dietary procedures. Ambulatory blood pressure monitoring will be performed at time -30 minutes (before juice or placebo intake), 0 hours, 3 hours, and 6 hours after juice or placebo intake. Saliva samples will be collected to assess nitrate reductase activity, and blood samples will be drawn to measure nitrate, nitrite, and nitrosothiol (nitric oxide metabolites), as well as to perform biochemical analyses of oxidative stress. Doppler ultrasound and Doppler velocimetry evaluation will be conducted at the peak action time of nitrate, which is estimated to occur three hours post-ingestion, based on previous research.