Acute Beetroot Juice Supplementation in Pre-eclampsia Pregnancies

Pre-eclampsia is a serious condition that typically affects pregnant women after the 20th week of pregnancy, characterized by high blood pressure and damage to organs such as the kidneys and liver. Currently, treatment options are limited, which has prompted researchers to explore alternative approaches. One such promising alternative is dietary nitrate found in vegetables like beetroot, as nitrate can be converted into nitric oxide in the body, which helps lower blood pressure. This study aims to determine the acute effects of nitrate-rich beetroot juice on blood pressure, several blood and salivary markers in pregnant women with pre-eclampsia. Furthermore, the study will assess fetal blood flow using Doppler ultrasound. The investigators want to understand the kinetics of nitrate and nitric oxide metabolites and assess the temporal dependency of the hypotensive response. Through this investigation, the investigators seek evidence of nitrate-enriched beetroot juice as an adjunct therapy in managing pre-eclampsia.

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.

Eligibility Criteria:
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 or late-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.
* Use of medications, except for antihypertensive.
* 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.