Association between Iron Deficiency with or without Anemia and Infants’ Cognitive, Motor, and Socio-emotional Development: Cross-sectional and Longitudinal analyses

Abstract

Background: Early child development is a major public health concern worldwide as it has long-term health and economic effects that extend beyond childhood. Iron deficiency (ID) is the most common micronutrient deficiency worldwide with the highest prevalence in low- and middle-income countries. ID may impact child development early in life. Objectives of this study were to investigate the relationship between ID and child development and to identify moderators of this association among infants.

Methods: Secondary data analyses of a nutritional and early learning controlled trial were performed. Participants: 513 children age 6-14 months from rural India were enrolled and followed for 12 months. Measures: At enrollment, 6-month and 12-month follow-up, child development was assessed using Mullen Scales for Early Learning (visual reception, fine/gross motor and receptive/expressive language domains) and Behavior Observation Inventory of the Bayley Scales of Infant and Toddler Development (socio-emotional domain). Analysis included linear mixed effects models accounting for village-level clustering (all aims) and repeated measures (Aims 2 and 3.1). To assess moderating effects of child age and sex, maternal education, household assets, and home environment, interaction terms were added in models.

Results: At enrollment, 47% of infants were girls, 72% had ID, 66% had anemia, and the mean age was 8.6 months. Mean maternal age was 23 years and 43% of mothers were anemic. Adjusted analyses found weak to no evidence of associations between ID and child development at enrollment or over a 12-month period. Child age and sex, maternal education, household assets, and home environment did not moderate associations of interest.

Conclusion and future directions: In this rural sample, ID was not associated with child development using observational study designs. In order to properly assess the onset and duration of ID and its associations with child development, further studies need to enroll pregnant women and follow up newborns during their first years of life. It is necessary to assess iron measures and child development at multiple time points throughout the study period.

Implications: Because of the pervasive nature of ID in this population, there is a need for nutritional interventions to reduce micronutrient deficiencies.