An interventional study of Nutritional intervention based on a Mediterranean diet in Gestational Diabetes Mellitus (GDM), Pregnancy and Mediterranean Diet, sponsored by Hospital San Carlos, Madrid. Not yet recruiting at 1 site in Spain. Open to female participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-09-16.
Sponsored by Hospital San Carlos, Madrid · Not applicable, Interventional, and Prevention
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:
Participants will:
877 studies on the registry are indexed under Diabetes, Gestational; 203 are open to participants now.
This study's planned enrollment of 1,200 is above the median of 110 across 564 interventional studies indexed under Diabetes, Gestational.
Browse Diabetes, Gestational studies →Hospital San Carlos, Madrid is the lead sponsor of 74 studies on the registry; 17 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
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
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.
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.
Time frame: From enrollment (gestational week 8-11) to the time of screening for gestational diabetes mellitus (gestational week 24-26)
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)
Time frame: 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).
Time frame: 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).
Time frame: From enrollment (gestational week 8-11) to delivery and immediate postpartum
Plan to share: 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).
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Hospital San Carlos, Madrid