Effect of a Mediterranean diet or stress reduction intervention during pregnancy on fetal brain volume and neonatal development: the IMPACT-BCN trial

To assess whether a Mediterranean diet (MD) or a Mindfulness-Based Stress Reduction (MBSR) intervention during pregnancy influences fetal brain volume and neonatal development. In a randomised clinical trial with parallel groups conducted at University Hospital in Barcelona, Spain (2017-2020), 1,221 pregnant women at high-risk for SGA were randomly allocated at 19-23 weeks of gestation into three groups: MD intervention, MBSR program or non-intervention. Participants in the MD group received monthly individual, group educational sessions and free provision of extra-virgin olive oil and walnuts. Women in the MBSR group underwent an 8-week MBSR program adapted for pregnancy. Women in the non-intervention group received pregnancy care as per institutional protocols. Randomly selected participants underwent a 3T magnetic resonance (MR) at 36.9 ± 0.6 weeks. 3D reconstruction and semiautomatic segmentation of the MR images were performed, where total brain volume (TBV) and regional volumes were assessed. Neonatal development was evaluated with the Neonatal Neurobehavioral Assessment Scale (NBAS) at 1-3 months. Compared to non-intervention group, MD fetuses had larger TBV (284.11cm3 vs. 294.01cm3, p = 0.04), larger corpus callosum volume (1.16cm3 vs. 1.26cm3, p = 0.03), and right frontal lobe volume (44.20cm3 vs. 46.60cm3, p = 0.02) at MR and higher scores in the NBAS clusters of autonomic stability [7.4 (0.9) vs. 7.6 (0.7); p = 0.04], social-interactive [7.5 (1.5) vs. 7.8 (1.3); p = 0.03], and range of state [4.3 (1.3) vs. 4.5 (1.0); p = 0.04]. MBSR fetuses had larger left anterior cingulate gyri (284.11cm3 vs. 294.01cm3, p = 0.04) at MR, and higher scores at NBAS in the neonatal regulation of state [6.0 (1.8) vs. 6.5 (1.5); p < 0.01]. Offspring whose mothers followed a MD or MBSR intervention during pregnancy have a different brain development than those without intervention; further research to elucidate the behind mechanisms is warranted.