Maternal seafood consumption and fetal growth: A review of the literature

Abstract

Studies in countries with high seafood and n-3 fatty acid (FA) consumptions have shown a benefit on fetal growth and child development. Maternal seafood intake is of great health interest since it constitutes an important source of n-3 FA but provides also an important pathway for fetal exposure to pollutants. This chapter reviews the literature on the association between maternal seafood and FA consumptions and fetal growth. Even if biological plausibility exists for n-3 FA in fatty fish or fish oil to delay spontaneous delivery, only half of the intervention studies were positive and concluded to an increase in gestational length associated with a supplementation with fish oil during pregnancy. Observational studies more often conclude to a positive association between fish intake and BW, independent of gestational age, although again this is far from an agreement. Surprisingly there are few animal studies on the effect of n-3 FA supplementation during pregnancy on BW. Confounding factors may explain the association in humans but results are robust to adjustment for fish contamination by pollutants (mercury) as well as maternal education or socioeconomic status or on intake of other food consumed more frequently by women who eat fish often, such as fruits and vegetables. At the moment, results of the different studies in the literature are too conflicting to recommend frequent fish intake to pregnant women as a means to prevent premature birth or intrauterine growth retardation. Given the evidence on the role of long-chain n-3 FA in brain and retina development, recommendation for fatty fish intake could be advocated. It remains to be proven that contamination by pollutants at low dose such as that currently found in women with frequent fish intake is not harmful for the child's motor and cognitive development.