Acute Beetroot Juice Supplementation in Pre-eclampsia Pregnancies

The study will include women diagnosed with either early-onset pre-eclampsia or late-onset pre-eclampsia, following the guidelines of the American College of Obstetricians and Gynecologists. Participants will be required to sign informed consent forms following a thorough explanation of the study. A total of four groups will be established, with twenty-four pregnant women randomly assigned to each group using a free online program. In each group (early-onset and late-onset pre-eclampsia), forty-eight pregnant women will receive nitrate-enriched beetroot juice (Beet It®, James White, UK), while another forty-eight will receive an equivalent amount of placebo juice. The trial will commence in the morning, between 7:30 and 8:30 am, after a standardized, low-nitrate breakfast provided by the hospital. Participants will be instructed to avoid nitrate-rich foods the previous evening and will receive guidance from the project team and the hospital's nutrition service. The hospital's nutritional team will oversee the dietary procedures. Ambulatory blood pressure monitoring will be conducted for six hours following the ingestion of juice or placebo. 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 two hours post-ingestion, based on previous research.