Effect of a Mediterranean Diet or Mindfulness-Based Stress Reduction During Pregnancy on Child Neurodevelopment A of the IMPACT BCN Randomized Clinical Trial

IMPORTANCE Maternal suboptimal nutrition and high stress levels are associated with adverse fetal and childhood neurodevelopment.OBJECTIVE To test the hypothesis that structured interventions based on a Mediterranean diet or mindfulness-based stress reduction (MBSR) during pregnancy improve child neurodevelopment at age 2 years.DESIGN, SETTING, AND PARTICIPANTS This was a prespecified analysis of the parallel-group Improving Mothers for a Better Prenatal Care Trial Barcelona (IMPACT BCN) randomized clinical trial, which was conducted at a university hospital in Barcelona, Spain, from February 2017 to March 2020. A total of 1221 singleton pregnancies (19 to 23 weeks' gestation) with high risk of delivering newborns who were small for gestational age were randomly allocated into 3 groups: a Mediterranean diet intervention, an MBSR program, or usual care. A postnatal evaluation with the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III), was performed. Data were analyzed from July to November 2022.INTERVENTIONS Participants in the Mediterranean diet group received monthly individual and group educational sessions and free provision of extra virgin olive oil and walnuts. Those in the stress reduction group underwent an 8-week MBSR program adapted for pregnancy. Individuals in the usual care group received pregnancy care per institutional protocols.MAIN OUTCOMES AND MEASURES Neurodevelopment in children was assessed by Bayley-III at 24 months of corrected postnatal age. RESULTS A total of 626 children (293 [46.8%] female and 333 [53.2%] male) participated at a mean (SD) age of 24.8 (2.9) months. No differences were observed in the baseline characteristics between intervention groups. Compared with children from the usual care group, children in the Mediterranean diet group had higher scores in the cognitive domain (13, 5.02; 95% CI, 1.52-8.53; P = .005) and social-emotional domain (13, 5.15; 95% CI, 1.18-9.12; P = .01), whereas children from the stress reduction group had higher scores in the social-emotional domain (13, 4.75; 95% CI, 0.54-8.85; P = .02).CONCLUSIONS AND RELEVANCE In this prespecified analysis of a randomized clinical trial, maternal structured lifestyle interventions during pregnancy based on a Mediterranean diet or MBSR significantly improved child neurodevelopmental outcomes at age 2 years.