Am J Clin Nutr

Background: Non-time-consuming and easy-to-administer dietary assessment tools specific for pregnancy are needed.

Objective: The aim of this validation study nested in the IMPACT BCN trial is to determine the concurrent validity of the 17-item pregnancy adapted Mediterranean diet score (preg-MEDAS) in participants of the IMPACT BCN (Improving Mothers for a better PrenAtal Care Trial BarCeloNa) trial and to analyze whether changes in the preg-MEDAS score were associated with maternal favorable dietary and cardiometabolic changes after 3-months of intervention in pregnant women.

Methods: Dietary data was collected in 812 participants by the preg-MEDAS and a 151-item validated food frequency questionnaire (FFQ) at baseline (19-23 week's gestation) and final (31-34 week's gestation). Concurrent preg-MEDAS validity was evaluated by Pearson and intra-class correlation coefficients, kappa statistic and Bland-Altman methods.

Results: The preg-MEDAS had a good correlation with FFQ (r=0.76 and intraclass correlation coefficient 0.75). The agreement of each of the preg-MEDAS items ranged from 40.9% to 93.8% with a substantial agreement mean concordance (kappa = 0.61). A 2-point increase in preg-MEDAS was associated with a decrease in maternal mean and systolic blood pressure (β = -0.51 mmHg, (95% CI -0.97, -0.04) and -0.87mmHg, (95% CI -1.48, -0.26), respectively).

Conclusion: The preg-MEDAS disclosed a good validity for assessing adherence to Mediterranean diet, allowing to detect dietary changes over time. In addition, changes observed in preg-MEDAS were significantly associated with a decrease in maternal blood pressure. Therefore, we propose preg-MEDAS as a rapid and simple dietary assessment tool during pregnancy.

Gov identifier: NCT03166332 (https://clinicaltrials.gov/ct2/show/NCT03166332).