Maternal Cod Intake during Pregnancy and Infant Development in the First Year of Life: Secondary Analyses from a Randomized Controlled Trial.

BACKGROUND Maternal seafood intake during pregnancy is associated with child neurodevelopment. No randomized controlled trials (RCTs) have examined the effect of maternal lean fish consumption during pregnancy on child neurodevelopment. OBJECTIVES The objective of the study was to examine the effect of increased maternal cod intake during pregnancy on infant general and socio-emotional development in the first year of life, and whether any effects observed were mediated by maternal iodine status. METHODS In an RCT, 133 pregnant women (≤19 weeks of gestation) were randomly assigned to receive 200 g cod fillet twice weekly (intervention) or to continue with their habitual diet (control) for 16 wk. The mothers completed the developmental screening questionnaires Ages and Stages Questionnaire, 2nd edition (ASQ-2) and Ages and Stages Questionnaire: Social-Emotional (ASQ:SE) when the infants were 3, 6, and 11 mo old. We compared scores between groups using linear mixed-effects models and examined whether iodine status postintervention mediated the effect on child development. RESULTS We found no difference between infants in the intervention and control groups on total ASQ-2 scores (P = 0.633), but a difference on the ASQ:SE scores in favor of the intervention group (20.9 and 20.5 in the intervention group and 26.1 and 26.8 in the control group for 3 and 6 mo, respectively; P = 0.020). There was no difference in change of the scores between the groups over time (P = 0.946). The effect of group on the total ASQ:SE scores was not mediated via maternal urinary iodine concentration postintervention (β = -1.03, SE = 0.68, P = 0.126). CONCLUSIONS Our results provide no evidence for an effect of increased cod intake during pregnancy on general child development in the first year of life, but there was a positive effect on socio-emotional problems. More studies are needed to define the role of fish consumption during pregnancy and the effects on child neurodevelopment.This trial was registered at clinicaltrials.gov as NCT02610959.