Association of Iron Status and Intake During Pregnancy with Neuropsychological Outcomes in Children Aged 7 Years: The Prospective Birth Cohort Infancia y Medio Ambiente (INMA) Study.

Victoria Arija,Jordi Sunyer,Sabrina Llop,Raquel Soler-Blasco,Jordi Julvez,Carmen Hernández-Martínez,Silvia Fernández-Barrés,Izaro Babarro,Josefa Canals,Jesús Ibarluzea,Jesús Vioque,Mónica Tous,Mónica Guxens

doi:10.3390/nu11122999

Abstract

Early iron status plays an important role in prenatal neurodevelopment. Iron deficiency and high iron status have been related to alterations in child cognitive development; however, there are no data about iron intake during pregnancy with other environmental factors in relation to long term cognitive functioning of children. The aim of this study is to assess the relationship between maternal iron status and iron intake during pregnancy and child neuropsychological outcomes at 7 years of age. We used data from the INMA Cohort population-based study. Iron status during pregnancy was assessed according to serum ferritin levels, and iron intake was assessed with food frequency questionnaires. Working memory, attention, and executive function were assessed in children at 7 years old with the N-Back task, Attention Network Task, and the Trail Making Test, respectively. The results show that, after controlling for potential confounders, normal maternal serum ferritin levels (from 12 mg/L to 60 mg/L) and iron intake (from 14.5 mg/day to 30.0 mg/day), respectively, were related to better scores in working memory and executive functioning in offspring. Since these functions have been associated with better academic performance and adaptation to the environment, maintaining a good state of maternal iron from the beginning of pregnancy could be a valuable strategy for the community.

Highlights

Brain undergoes developmental changes throughout the different stages of the prenatal period, infancy, childhood, and adolescence
In relation to the maternal levels of serum ferritin (SF) measured in the first period, we observed that there are no pregnant woman with iron deficiency (ID) or iron deficiency anemia (IDA) in the SF group >12 mg/L, as it was expected
We assessed the association of both maternal iron status and total iron intake during pregnancy with cognitive functioning of children aged 7 years from the Spanish Infancia y Medio Ambiente study (INMA)

Summary

Introduction

Brain undergoes developmental changes throughout the different stages of the prenatal period, infancy, childhood, and adolescence. It has been suggested that ID during pregnancy may have effects in early life [5,6,21,22,23,24] but could be related to long-term alterations in cognitive, behavior, and social development and poorer school performance during childhood and adolescence [3,12,25,26,27]. A review concluded that the influence of maternal iron status during pregnancy on the cognitive function of offspring is inconclusive [13,28,29]. Iron plays a crucial role in neurodevelopment processes (neuronal growth, myelinization, and neurotransmitter synthesis) that take place mainly in the third trimester of pregnancy, and few studies have assessed the iron status at that time [28]

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