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In developed countries, iron deficiency (ID) remains a nutritional problem.Our earlier results from a largely middle class population emphasize the widespread prevalence of ID among pregnant women and infants in Canada.However,the impact of maternal ID on pregnancy outcomes is not well understood despite an increasing number of studies over the past 20 years.Iron plays an important role in central nervous system (CNS) development.It is essential for neurotransmitter synthesis and CNS myelination.In children, postnatal ID is associated with decreased cognitive performance, motor deficit and behavioural problems.The mechanism by which maternal ID impacts on infants CNS development is unknown but it could be associated with changes in essential fatty acid and eicosanoid metabolism.In a previous study, we fed female guinea pigs an iron sufficient (IS) or deficient (ID) diet for 14 days before mating and throughout pregnancy and lactation.The pups were tested for spatial memory on post-natal days 4-7 using exploration and object recognition tasks in an open field.On postnatal day 9, the biochemical analysis included the pups brain fatty acid profiles, prostaglandin (PGE2 and PGF2α) concentrations and cyclooxygenase Ⅱ protein levels.Spatial memory and indices of eicosanoid metabolism were comparable in both dietary groups.However, n-3 fatty acids were significantly higher and saturated fatty acids lower in brain of pups from the ID group.The data suggest that maternal iron deficiency results in a modification of the fatty acid profile of the offsprings brain that is not associated with any spatial memory deficits during early development.Comparable results were obtained in older animal.We also showed that ID induced during pregnancy and lactation affected the auditory acuity of offspring as measured by an elevation of the ABR threshold even after the normalization of iron in the diet after weaning.This altered auditory acuity induced by the mild ID diet was observed on lower and higher frequencies (2, 16 and 32 kHz).The negative effects induced by maternal ID during pregnancy and lactation on the offsprings auditory brain stem responses are potentially irreversible.Currently in Canada, infants born from iron-deficient mothers have not been identified as being at risk for health problems.Given the potential detrimental impact of maternal anemia on the infants health and development, it is critical to address this problem.