Effect of an Early and Intensified Nutritional Intervention on the Risk of Developing Gestational Diabetes Mellitus

NCT07817017 | Not Yet Recruiting DMC

• 2 other identifiers: PI25_0141325/902-EC_X
• Study Type: interventional
• Target: 1,200
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if a nutritional intervention based on a Mediterranean diet (MedDiet), initiated early in pregnancy, reduces the incidence of gestational diabetes mellitus (GDM) and other adverse maternal, fetal and obstetric events in pregnant women considered high-risk. It will also learn about the stratification of GDM risk based on clinical, anthropometric, analytical and genetic characteristics. The main questions it aims to answer are:

• Does the nutritional intervention based on MedDiet reduce the incidence of GDM in women with high risk?
• How can we stratify the risk of GDM? Researchers will compare an advanced nutritional intervention based on a Mediterranean diet to standard care (general recommendations given at the beginning of pregnancy). Participants will:
• Receive intensive nutritional counselling or standard regular recommendations during the first trimester of pregnancy.
• Visit the clinic at the time of the first ultrasound (gestational week 8-11) and at the time of screening for GDM (gestational week 24-26).
• Undergo a genetic test performed with a buccal swab.

Conditions

Gestational Diabetes Mellitus (GDM); Pregnancy; Mediterranean Diet

Keywords

gestational diabetes mellitus; pregnancy; mediterranean diet; poligenic risk score; genetic polymorphism

Outcome Measures

Primary Outcomes (1)

• Incidence of gestational diabetes mellitus

  The general objective of this study is to determine whether an advanced nutritional intervention based on Mediterranean diet reduces the incidence of gestational diabetes mellitus and other adverse maternal-fetal obstetric and endocrine-metabolic events in pregnant women considered high-risk based on a risk score derived from the interaction between associated genetic polymorphisms, baseline clinical characteristics, and anthropometric characteristics of pregnant women. The primary outcome is the comparison of the frequency of GDM, according to IADPSG criteria, between the MedDiet intervention group and the standard treatment group in women at high risk according to the calculated risk of developing GDM.

  From enrollment (gestational week 8-11) to the time of screening for gestational diabetes mellitus (gestational week 24-26)

Secondary Outcomes (3)

• Frequency of maternal complications

  From enrollment (gestational week 8-11) to delivery

• Frequency of fetal complications

  From enrollment (gestational week 8-11) to delivery and neonatal period

• Frequency of obstetric complications

  From enrollment (gestational week 8-11) to delivery and immediate postpartum

Study Arms (2)

Standard treatment

NO INTERVENTION

The nutritional intervention will consist of providing information on healthy lifestyle measures through an 8-minute informational video (accessible via QR code at the consultation room or the permanent link https://www.youtube.com/watch?v=Qgcz5t9B9WI). Routine obstetric follow-up does not involve subsequent monitoring of adherence to these recommendations, beyond the usual follow-up.

Advanced treatment

EXPERIMENTAL

A specific nutritional intervention consisting of a group session that will last approximately one hour, led by a nutritionist from the research team. This session will explain in detail the key aspects of the MedDiet: consumption of \>40 ml/day of extra virgin olive oil, 30 g of nuts per day, 3-4 pieces of whole fruit (not juice), homemade stir-fries, 2-3 servings of vegetables and/or salads per day, 2-3 servings per day of low-fat dairy products, whole grains, 2-3 servings of legumes per week, consumption of fish, limiting the consumption of red meat, and avoiding ultra-processed products, sliced bread, soft drinks, juices, fast food, and pre-cooked products. Two telephonic interviews will be scheduled for follow-up around gestational weeks 16 and 20 to provide motivation and assess and reinforce adherence to these recommendations.

Other: Nutritional intervention based on a Mediterranean diet

Interventions

Nutritional intervention based on a Mediterranean diet OTHER

The nutritional intervention consists of a 1-hour group session led by a nutritionist from the research team. Includes a detailed description of the key aspects of the MedDiet: consumption of \>40 ml/day of extra virgin olive oil, 30 g of nuts per day, 3-4 pieces of whole fruit (not juice), homemade stir-fries, 2-3 servings of vegetables and/or salads per day, 2-3 servings per day of low-fat dairy products, whole grains, 2-3 servings of legumes per week, consumption of fish, limiting the consumption of red meat, and avoiding ultra-processed products, sliced bread, soft drinks, juices, fast food, and pre-cooked products. In addition, 2 telephonic interviews for follow-up (gestational weeks 16 and 20) to reinforce adherence and emphasize consumption of \>40 ml/day of extra virgin olive oil, 30 g of nuts per day, 3-4 pieces of whole fruit (not juice), daily vegetables and daily physical activity.

Advanced treatment

Eligibility Criteria

• Age: 18 Years - 50 Years
• Gender Eligibility Details: Pregnant women
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Unassisted single pregnancy;
• Age between 18 and 50 years old;
• Fasting blood glucose \<92 mg/dl in the first gestational blood test;
• First trimester ultrasound before the 12th gestational week.

You may not qualify if:

• Multiple or assisted pregnancies;
• Any pregestational illness or pregestational treatment that may affect pregnancy;
• Known intolerance/allergy to any component of the nutritional intervention.

Sponsors & Collaborators

• Hospital San Carlos, Madrid: lead

Study Sites (1)

Hospital Clínico San Carlos

Madrid, Madrid, 28040, Spain

Location

MeSH Terms

Conditions

Diabetes, Gestational

Condition Hierarchy (Ancestors)

Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases

Central Study Contacts

Ana M. Ramos-Levi, MD., PhD.

CONTACT

+33696938427; ana_ramoslevi@hotmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator. M.D., PhD.

Study Record Dates

• First Submitted: September 8, 2026
• First Posted: September 14, 2026
• Study Start: September 15, 2026
• Primary Completion (Estimated): October 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: September 16, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF

Locations

ES (1)