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.

• Pre-eclampsia pregnat women

Inclusion criteria

• Pregnant women at or beyond the 20th week of gestation.
• Hospitalized at Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto.
• Diagnosed with early-onset pre-eclampsia confirmed by a medical professional.
• Capacity to provide written informed consent for study participation.

Exclusion criteria

• Multiple pregnancies.
• Uncontrolled arterial hypertension (Systolic Blood Pressure > 160 mmHg or Diastolic Blood Pressure > 100 mmHg).
• Pregnant women with a body mass index > 40 kg/m²
• Severe gestational complications.
• History of food allergy with hypersensitivity to beetroot.
• Smokers.
• Chronic alcohol consumption.
• Medications such as non-steroidal anti-inflammatory drugs, nasal decongestants, users of proton pump inhibitors and H2 receptor antagonists or any other medication that interferes with stomach pH.
• Diagnosis of renal or hepatic disease affecting nitrate metabolism.
• Cardiac conditions such as moderate to severe congestive heart failure and coronary artery disease.
• Pre-existing type 1 or type 2 diabetes.
• Healthy Pregnant Women

Inclusion criteria

• Healthy pregnant women at or beyond the 20th week of gestation.
• Absence of pre-eclampsia diagnosis or other obstetric complications.
• Willingness and ability to remain admitted at the Clinical Research Unit for the - period required by the study.
• Capacity to provide written informed consent for study participation.

Exclusion criteria

• The same exclusion criteria from Pre-eclampsia group apply.