Relationship between maternal DHA and iron status and infants' cognitive performance

The dietary nutrients iron and long-chain polyunsaturated fatty acids are believed to play an important role in early brain development. We investigated the relationship between pregnant women's iron and docosahexaenoic acid (DHA) status and their infants' cognitive performance at age six months.

Blood iron and DHA status were analyzed in pregnant women at 28 to 32 weeks of gestation. The women's dietary habits, sociodemographic background, and cognitive performance were assessed using questionnaires. At age six months, infants' blood hemoglobin was analyzed, feeding practices assessed, and weight, length, and head circumference recorded. Each infant's cognitive performance was assessed using the Brunet-Lézine Scale of Psychomotor Development of Early Childhood and the Bayley Scales of Infant Development. Sixty-three mother-infant dyads completed the study.

During pregnancy, 9.5% of pregnant women were anemic, 34.9% had low iron stores, and 3.2% suffered from iron deficiency anemia. The DHA represented 4.36% and 2.15% in erythrocyte and plasma total fatty acids, respectively. These levels were considered adequate. No significant relationship was observed between gestational iron or DHA status and infants' cognitive performance.

In this small group of infants born to mothers with relatively good feeding practices and a privileged socioeconomic background, cognitive testing with the instruments above was not associated with maternal iron and DHA levels at age six months.