Intra-uterine maternal haemoglobin concentration is associated with cognitive function in stunted adolescents: results from a 17-year retrospective cohort study in Indonesia

Background and objectives: Maternal anaemia is a major public health problem that has a negative impact on the neurodevelopment of children under the age of five, but its impact on long-term cognitive performance is largely unknown. This study aims to investigate the association between intra-uterine maternal haemoglobin (Hb) concentration and cognitive function of their offspring during adolescence. Methods: We performed secondary analysis on the retrospective cohort data of 363 paired pregnant mothers and their offspring at 10-14 years of age from the Indonesia Family Life Survey (IFLS) conducted in 1997 - 2014. Cognitive function was measured as the total score on the Raven's Progressive Matrices test. Multiple linear regression models with maternal Hb as exposure and cognitive function as outcome were explored, with adjustments for maternal age, maternal height, and socioeconomic status. Results: The weighted anaemia prevalence was 49.3% in pregnant mothers and 22.2% in adolescents. The mean total cognitive score of adolescents was 12.4 out of 17. Adolescents who were stunted, anaemic, and living in a rural area had a significantly lower cognitive score than their counterparts. In the adjusted model, maternal Hb was not associated with adolescent cognitive function (β: 0.14; 95%CI: -0.05 – 0.34). However, the effect of maternal Hb level on cognitive function of their offspring was modified by stunting status (stunted β: 0.44; 95%CI: 0.05 – 0.82 and non-stunted β: 0.01; 95%CI: -0.02 – 0.24). Conclusions: For each 1 g/dL increase in Hb, cognitive scores increased by 0.44, but only in stunted adolescents. This study shows that adverse cognitive outcomes at adolescent age is likely multi-causal and can best be addressed by tackling pregnancy-related anaemia as well as warranting good nutrition for growth and development during childhood.