Effectiveness on maternal and offspring metabolic control of a home-based dietary counseling intervention and DHA supplementation in obese/overweight pregnant women (MIGHT study): A randomized controlled trial-Study protocol

Background: Lifestyle interventions are the primary prevention strategy for gestational diabetes (GDM) in obese/overweight women; however, these interventions have shown limited effectiveness. Omega-3 polyunsaturated fatty acids (PUFAs) intake has shown beneficial effects on glucose metabolism, lipid fractions and inflammatory factors in women who already have GDM. Combining PUFAs supplementation with a lifestyle intervention could achieve lower increase of glucose levels by improving insulin sensitivity. Our aim is to assess two prenatal nutritional interventions (home-based dietary counseling and/or docosahexaenoic acid (DHA) supplementation) delivered to obese/overweight women during pregnancy for them and their offspring to achieve better metabolic control. Methods/design: Randomized controlled trial, 2 x 2 factorial design. Eligible pregnant women will be randomly allocated to one of the four parallel arms: 1) Home-based dietary counseling + 800 mg/day DHA supplementation (n = 250); 2) 800 mg/day DHA (n = 250); 3) Home-based dietary counseling + 200 mg/day DHA (n = 250); 4) 200 mg/day DHA (n = 250). Primary outcomes are: GDM; macrosomia; and neonatal insulin resistance. Data analyses will be done on an intention-to-treat basis. Discussion: We expect the present study to contribute to the understanding of the potential effectiveness of an omega-3 supplementation on the risk of developing GDM in overweight/obese pregnant women. We will also test if the combination of having better dietary habits alongside with omega 3 supplementation will improve insulin sensitivity and as consequence, a lower elevation of glucose levels could be achieved.