Relation of maternal zinc nutriture to pregnancy outcome and infant development in an Egyptian village

Abstract

Zinc nutriture of women living in a periurban Egyptian village was examined over the last 6 mo of pregnancy and the first 6 mo of lactation as one of several potential determinants of pregnancy outcome and infant development. Estimated bioavailable zinc intake was approximately 2 mg/d from diets high in phytate and fiber. Among numerous variables analyzed by multiple regression, early pregnancy weight (3 mo) and plasma zinc concentrations in the second trimester formed the best predictor model of birth weight, accounting for 39% of the variance. Bioavailable zinc intake during pregnancy was part of a profile of micronutrient intakes related to neonatal habituation behavior, a measure of early information processing. Performance on the Bayley motor test at 6 mo of age was negatively related to maternal intakes of plant zinc, phytate, and fiber, suggesting that zinc bioavailability was involved. Maternal dietary intake explained most of the variance observed in infant motor performance; however, predictive variance was amplified by the psychosocial context.

The Role of Nutrition in Children's Neurocognitive Development, From Pregnancy Through Childhood

“…However, the relationship between maternal zinc status and the child's cognitive development has not been fully investigated. In an observational study, low maternal zinc intake in Egyptian mothers was associated with lower levels of focused attention in newborns, measured with the Brazelton Neonatal Behavior Assessment Scale (Kirksey et al, 1994). Surprisingly, a placebo controlled randomized trial undertaken on poor Bangladeshi mothers found that 13 months old infants of zinc supplemented mothers scored less on the Bayley scales of infant development than infants born to mothers who received a placebo (Hamadani et al, 2002).…”

Potential contribution of maternal zinc supplementation during pregnancy to maternal and child survival

“…Kirksey et al (77) observed positive associations between maternal serum zinc concentrations during pregnancy and the developmental status of Egyptian newborns assessed by using the Brazelton Neonatal Behavioral Assessment Scale (78). Subsequently, Kirksey et al (8) reported that positive associations were still observed between maternal zinc status during pregnancy and infant developmental status when assessed at 6 mo of age by using the Bayley Scales of Infant Development (79).…”

“…Importantly, the orientation and habituation components of both these tests were associated most strongly with maternal zinc status, and these are believed to relate directly to cognitive ability later in life (8). Orientation refers to the ability of the infant to respond appropriately to an environmental stimulus, whereas habituation refers to the ability of the infant to inhibit response to a repetitive or familiar environmental stimulus.…”

“…Tamura and Goldenberg (6) compiled 27 studies reporting dietary zinc intakes of women of childbearing age worldwide. Of these, 2 studies from developing countries [Guatemala and Egypt (7,8)] reported average usual intakes of 8-11 mg Zn/d and 2 studies of intakes of south Asians living in the United Kingdom (9, 10) reported usual intakes of 5-10 mg Zn/d. Most of the studies cited were conducted in the United States and United Kingdom, and average usual zinc intakes were reported to be in the range 8-14 mg/d across the studies.…”

“…Consequences of maternal zinc deficiency on birth outcomes and maternal and perinatal health. (8,20,22,26,27,28,(32)(33)(34) and 5 reported negative associations (37,39,40,42,48). Various reasons for these differences in associations can be postulated, including differences in 1) timing of the assessment (blood draw) during pregnancy and the effects of hemodilution, 2) laboratory methods and quality, 3) sample size and the potential for influential values to drive associations, and 4) the underlying zinc nutriture of the populations.…”