OC19.05: *Effects of Mediterranean diet or mindfulness‐based stress reduction on infant neurodevelopment at two years of age

To investigate whether maternal lifestyle interventions during pregnancy based on Mediterranean diet or mindfulness-based stress reduction (MBSR) improve infant neurodevelopment at two years. Prespecified secondary analysis of a randomised clinical trial (IMPACT BCN Trial) (2017-2020), which included 1221 singleton pregnancies at high-risk for small for gestational age newborn. Participants were randomly allocated at 19-23 weeks' gestation into three groups: a Mediterranean diet intervention, a MBSR or usual care. A postnatal evaluation with the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III) was performed in 626 infants at a mean (SD) of 24.8 (2.9) months. Compared with infants from the usual care group, toddlers in the Mediterranean diet group had higher scores in the cognitive [b (95%CI); 5.02 (1.52 to 8.53); p < 0.01], and social-emotional domain [b (95%CI); 5.15 (1.18 to 9.12); p = 0.01], whereas infants from the MBSR group had higher scores in the social-emotional domain [b (95%CI); 4.75 (0.54 to 8.85); p = 0.02]. These differences remained similar after adjusting for maternal socioeconomic status and fetal sex. Mediterranean diet score showed significant positive associations with the cognitive and language Bayley-III domains, whereas levels of maternal stress and anxiety during pregnancy showed negative significant associations with all five Bayley-III domains. Maternal structured lifestyle intervention during pregnancy significantly improved infant neurodevelopmental outcome at two years of corrected age. This is the first randomised trial evaluating the effects of pregnancy lifestyle interventions on infant neurodevelopment.