The impacts of maternal iron deficiency and being overweight during pregnancy on neurodevelopment of the offspring

Both maternal Fe deficiency (ID) and being overweight or obese (Ow/Ob, BMI >= 25 kg/m(2)) may negatively affect offspring brain development. However, the two risk factors correlate and their independent effects on infant neurodevelopment are unclear. PREOBE is a prospective observational study that included 331 pregnant Spanish women, of whom 166 had pre-gestational Ow/Ob. Fe status was analysed at 34 weeks and at delivery, and babies were assessed using Bayley III scales of neurodevelopment at 18 months. In confounder-adjusted analyses, maternal ID at 34 weeks was associated with lower composite motor scores at 18 months (mean 113.3 (SD 9.9) v. 117.1 (SD 9.2), P=0.039). Further, the offspring of mothers with ID at delivery had lower cognitive scores (114.0 (SD 9.7) v. 121.5 (SD 10.9), P = 0.039) and lower receptive, expressive and composite (99.5 (SD 8.6) v. 107.6 (SD 8.3), P= 0.004) language scores. The negative associations between maternal ID at delivery and Bayley scores remained even when adjusting for maternal Ow/Ob and gestational diabetes. Similarly, maternal Ow/Ob correlated with lower gross motor scores in the offspring (12.3 (SD 2.0) v. 13.0 (SD 2.1), P = 0.037), a correlation that remained when adjusting for maternal ID. In conclusion, maternal ID and pre-gestational Ow/Ob are both negatively associated with Bayley scores at 18 months, but independently and on different subscales. These results should be taken into account when considering Fe supplementation for pregnant women.