Gestational Diabetes Mellitus (GDM)MedDiet in GDMNCT07817017
Effect of an Early and Intensified Nutritional Intervention on the Risk of Developing Gestational Diabetes Mellitus
A study testing Nutritional intervention based on a Mediterranean diet in people with Gestational Diabetes Mellitus (GDM) and Pregnancy, run by Hospital San Carlos, Madrid at 1 site in Spain.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women only
- Conditions the study is for
- Gestational Diabetes Mellitus (GDM), Pregnancy, Mediterranean Diet
- What is being tested?
- Nutritional intervention based on a Mediterranean diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,200 participants
- Where
- 1 siteSpain
- Study dates
- 15 Sep 2026to 31 Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- 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.
Who cannot join
- Multiple or assisted pregnancies;
- Any pregestational illness or pregestational treatment that may affect pregnancy;
- Known intolerance/allergy to any component of the nutritional intervention.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Spain1 site
Hospital Clínico San Carlos
Madrid, Madrid, 28040
Ana M. Ramos-Levi, M.D., PhD., +34696938427, ana_ramoslevi@hotmail.com
About this study
Official title: Effect of an Early and Intensified Nutritional Intervention Based on a Mediterranean Diet (MedDiet) in Women With Clinical-genetic Risk of Developing Gestational Diabetes Mellitus (GDM): a Randomized, Parallel, Interventional, Controlled Clinical Trial
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:
Read more
- 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.
- Being tested
- Nutritional intervention based on a Mediterranean diet
- Keywords
- gestational diabetes mellitus, pregnancy, mediterranean diet, poligenic risk score, genetic polymorphism
- Medical subject headings
- Diabetes, Gestational
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nutritional intervention based on a Mediterranean dietOther
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Other: Nutritional intervention based on a Mediterranean diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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
Frequency of maternal complications between the MedDiet intervention group and the standard treatment group in women at high risk according to the calculated risk of developing GDM. Variables for this outcome include: maternal weight, weight gain; risk score; frequency of maternal complications (hypertension, eclampsia, infections, carbohydrate metabolism disorders - defined as alterations in normal levels of at least one of the following: fasting glucose, HbA1c, C-peptide, insulin, HOMA-IR)
Measured: From enrollment (gestational week 8-11) to delivery
Frequency of fetal complications
Comparison of the frequency of fetal complications between the MedDiet intervention group and the standard treatment group in high-risk women, based on the calculated risk of developing gestational diabetes mellitus (GDM). Variables for this outcome include: birth weight, hypoglycemia, potassium abnormalities, calcium abnormalities, polycythemia, admission to the neonatal intensive care unit (NICU).
Measured: From enrollment (gestational week 8-11) to delivery and neonatal period
Frequency of obstetric complications
Comparison of the frequency of obstetric complications between the MedDiet intervention group and the standard treatment group in women at high risk of developing GDM. Variables for this outcome include: type of delivery, dystocia, lacerations during delivery, preterm or postterm delivery (gestational week at delivery).
Measured: From enrollment (gestational week 8-11) to delivery and immediate postpartum
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Sep 2026
- Study start15 Sep 2026 (estimated)
- Primary completion31 Oct 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gestational Diabetes Mellitus (GDM)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 1,200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital San Carlos, Madrid
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ana M. Ramos-Leví, Hospital San Carlos, Madrid
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07817017
- Sponsor's protocol ID
- PI25_01413
- Other IDs
- 25/902-EC_X
- Acronym
- MedDiet in GDM
- Status last verified
- Jun 2026
- First submitted
- 8 Sep 2026
- Last updated
- 16 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The original protocols of the study will be stored in a locked office in the Department of Endocrinology at our Hospital. De-identified data will be saved on a secure electronic database. Specifically, we will use REDCap® (Vanderbilt University) software, which is known to be a secure, browser-based web application (http://project-redcap.org), for data entry and analysis. All participant data related to the study, including scales and questionnaires, will be completed in paper form, and will then be recorded and uploaded in the REDCap®Electronic Data Collection Record (eCRD).
Study at a glance
From the registry record, last updated by the sponsor on 16 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of an Early and Intensified Nutritional Intervention Based on a Mediterranean Diet (MedDiet) in Women With Clinical-genetic Risk of Developing Gestational Diabetes Mellitus (GDM): a Randomized, Parallel, Interventional, Controlled Clinical Trial
- ClinicalTrials.gov ID
- NCT07817017
- Acronym / sponsor ID
- MedDiet in GDM / PI25_01413
- Keywords
- gestational diabetes mellitus, pregnancy, mediterranean diet, poligenic risk score, genetic polymorphism
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 1,200 participants (estimated)
- Lead sponsor
- Hospital San Carlos, MadridUniversity, hospital or other
- Study start
- 15 Sep 2026 (estimated)
- Primary completion
- 31 Oct 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 14 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 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 | Other: Nutritional intervention based on a Mediterranean dietA 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. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (3 listed)
- Multiple or assisted pregnancies;
- Any pregestational illness or pregestational treatment that may affect pregnancy;
- Known intolerance/allergy to any component of the nutritional intervention.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nutritional intervention based on a Mediterranean dietThe 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. | Other | Advanced treatment |
Primary outcome
Incidence of gestational diabetes mellitus
Time frame: From enrollment (gestational week 8-11) to the time of screening for gestational diabetes mellitus (gestational week 24-26)
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.
3 secondary outcomes
Frequency of maternal complications
Time frame: From enrollment (gestational week 8-11) to delivery
Frequency of fetal complications
Time frame: From enrollment (gestational week 8-11) to delivery and neonatal period
Frequency of obstetric complications
Time frame: From enrollment (gestational week 8-11) to delivery and immediate postpartum
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Sep 2026.
- Individual participant dataSharing planned: Yes. The original protocols of the study will be stored in a locked office in the Department of Endocrinology at our Hospital. De-identified data will be saved on a secure electronic database. Specifically, we will use REDCap® (Vanderbilt University) software, which is known to be a secure, browser-based web application (http://project-redcap.org), for data entry and analysis. All participant data related to the study, including scales and questionnaires, will be completed in paper form, and will then be recorded and uploaded in the REDCap®Electronic Data Collection Record (eCRD).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nutritional intervention based on a Mediterranean diet in people with Gestational Diabetes Mellitus (GDM) and Pregnancy, run by Hospital San Carlos, Madrid at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 16 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ana M. Ramos-Levi, MD., PhD. (+33696938427, ana_ramoslevi@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of gestational diabetes mellitus (time frame: From enrollment (gestational week 8-11) to the time of screening for gestational diabetes mellitus (gestational week 24-26)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Sep 2026.