Polyphenol Intake, Mediterranean Diet Adherence, and Oxidative Stress in Pregnancy (PREGPOLY)

June 14, 2026 updated by: Ana García Albarrán, University of Salamanca

Effect of Polyphenol Intake and Adherence to the Mediterranean Diet on Oxidative Stress During Pregnancy

This study is a randomized controlled clinical trial designed to evaluate the effect of a polyphenol-rich dietary intervention during pregnancy on endothelial function, oxidative stress biomarkers, and maternal and neonatal outcomes.

Pregnancy is associated with metabolic and vascular adaptations, and complications such as gestational diabetes and hypertensive disorders are linked to endothelial dysfunction and increased oxidative stress. Dietary factors, particularly adherence to the Mediterranean diet and intake of polyphenol-rich foods, may play a protective role.

Pregnant women will be randomly assigned to either an intervention group or a control group. The intervention consists of daily consumption of 10 g of natural non-alkalized cocoa and structured dietary counseling aimed at achieving at least five daily servings of fruits and vegetables, alongside general Mediterranean diet recommendations.

The intervention will last 12 weeks, from early to mid-pregnancy. Biomarkers of endothelial function and oxidative stress will be measured at different time points, along with clinical maternal outcomes (including gestational diabetes and hypertensive disorders) and neonatal outcomes.

The aim is to determine whether this dietary intervention improves endothelial function, reduces oxidative stress, and contributes to better pregnancy outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

  • Name: María Begoña Ayuda Durán, PharmD
  • Phone Number: +34 923 294 537
  • Email: bego_ayuda@usal.es

Study Locations

  • Spain
    • SALAMANCA
      • Salamanca, SALAMANCA, Spain, 37007

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Pregnant women aged 18 years or older.
  • Singleton pregnancy.
  • Gestational age between 8 and 11 weeks at enrollment.
  • Receiving prenatal care within the Salamanca Health Area.
  • Able to understand the study information and provide written informed consent.
  • No clinical restrictions that would contraindicate dietary modifications.

Exclusion Criteria:

  • Medical or obstetric conditions that contraindicate dietary modifications.
  • Active metabolic, renal, or hepatic disease.
  • Severe hyperemesis gravidarum or gastrointestinal disorders limiting food intake.
  • Allergy or intolerance to cocoa.
  • Habitual high cocoa or chocolate consumption (>30 g/day).
  • Multiple pregnancy.
  • Severe obstetric complications diagnosed before enrollment.
  • Inability to comply with study procedures, attend follow-up visits, or communication barriers that could interfere with participation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Intervention Group
Participants will receive a daily dietary intervention consisting of 10 g of natural non-alkalized cocoa and structured nutritional counseling aimed at achieving at least five daily servings of fruits and vegetables, in addition to general Mediterranean diet recommendations. The intervention will last 12 weeks during pregnancy.
Dietary supplement: Natural Non-Alkalized Cocoa
Structured nutritional counseling aimed at achieving at least five daily servings of fruits and vegetables and improving adherence to the Mediterranean diet.
Behavioral: Polyphenol-Rich Dietary Counseling
Structured nutritional counseling aimed at achieving at least five daily servings of fruits and vegetables and improving adherence to the Mediterranean diet.
Active Comparator: Control Group
Participants will receive standard dietary advice based on general healthy eating and Mediterranean diet recommendations during pregnancy, without specific supplementation or structured dietary intervention.
Behavioral: Polyphenol-Rich Dietary Counseling
Structured nutritional counseling aimed at achieving at least five daily servings of fruits and vegetables and improving adherence to the Mediterranean diet.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in serum sVCAM-1 concentration
Time Frame: Baseline, 24-28 weeks, and 32-36 weeks of gestation
Change in serum soluble vascular cell adhesion molecule-1 (sVCAM-1) levels from baseline to 24-28 weeks of gestation, measured in [ng/mL].
Baseline, 24-28 weeks, and 32-36 weeks of gestation
Change in serum sFlt-1/PlGF ratio
Time Frame: Baseline, 24-28 weeks of gestation, and 32-36 weeks of gestation.
Change in the soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) ratio from baseline to 24-28 weeks and 32-36 weeks of gestation.
Baseline, 24-28 weeks of gestation, and 32-36 weeks of gestation.
Change in serum nitric oxide concentration
Time Frame: Baseline, 24-28 weeks, and 32-36 weeks of gestation.
Change in serum nitric oxide (NO) concentration from baseline to 24-28 weeks and 32-36 weeks of gestation, measured in [pg/mL].
Baseline, 24-28 weeks, and 32-36 weeks of gestation.
Change in serum IL-6 concentration
Time Frame: Baseline, 24-28 weeks, and 32-36 weeks of gestation
Change in circulating interleukin-6 levels between baseline and follow-up assessments, measured in [pg/mL].
Baseline, 24-28 weeks, and 32-36 weeks of gestation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Mediterranean Diet Adherence Screener (MEDAS) score
Time Frame: Baseline, 24-28 weeks of gestation, and 32-36 weeks of gestation.
Change in adherence to the Mediterranean diet measured using the Mediterranean Diet Adherence Screener (MEDAS). Scores range from 0 to 14, with higher scores indicating greater adherence to the Mediterranean diet.
Baseline, 24-28 weeks of gestation, and 32-36 weeks of gestation.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of gestational diabetes mellitus
Time Frame: 24-28 weeks of gestation.
Occurrence of gestational diabetes mellitus diagnosed according to standard clinical criteria and routine screening procedures during pregnancy.
24-28 weeks of gestation.
Incidence of gestational hypertension
Time Frame: From enrollment until delivery.
Occurrence of gestational hypertension diagnosed according to standard clinical criteria during pregnancy.
From enrollment until delivery.
Incidence of preeclampsia
Time Frame: From enrollment until delivery.
Occurrence of preeclampsia diagnosed according to standard clinical criteria during pregnancy.
From enrollment until delivery.
Gestational age at delivery
Time Frame: At delivery.
Gestational age at the time of delivery measured in completed weeks of gestation.
At delivery.
Neonatal birth weight
Time Frame: At delivery.
Neonatal birth weight measured in grams.
At delivery.
Apgar score at 1 minute
Time Frame: At delivery.
Neonatal condition assessed using the Apgar score at 1 minute after birth. Scores range from 0 to 10, with higher scores indicating better neonatal condition.
At delivery.
Apgar score at 5 minutes
Time Frame: At delivery.
Neonatal condition assessed using the Apgar score at 5 minutes after birth. Scores range from 0 to 10, with higher scores indicating better neonatal condition.
At delivery.
Apgar score at 10 minutes
Time Frame: At delivery.
Neonatal condition assessed using the Apgar score at 10 minutes after birth. Scores range from 0 to 10, with higher scores indicating better neonatal condition.
At delivery.
Neonatal intensive care unit admission
Time Frame: At delivery
Proportion of newborns requiring admission to the neonatal intensive care unit (NICU).
At delivery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Salamanca

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ana García Albarrán, RN, Midwife, University of Salamanca
  • Study Director: Susana González Manzano, PharmD, University of Salamanca
  • Study Director: María Begoña Ayuda Durán, PharmD, University of Salamanca

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 9, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • USAL-CT-2026-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

At present, there is no finalized plan for sharing individual participant data (IPD). Due to the sensitive nature of maternal and neonatal health data and the presence of biological and clinical information, data sharing will be considered in accordance with institutional ethics requirements, participant consent, and applicable data protection regulations.

Any potential future sharing of de-identified data will be determined after study completion and in line with publication and regulatory requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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