文摘
Maternal fish consumption brings both risks and benefitsto the fetus from the standpoint of methylmercury (MeHg)and n-3 PUFA (polyunsaturated fatty acids). MeHg isone of the most risky substances to come through fishconsumption, and mercury concentrations in red blood cells(RBC-Hg) are the best biomarker of MeHg exposure.Docosahexaenoic acid (DHA, C22:6n-3), which is one ofthe most important fatty acids for normal brain developmentand function, is also derived from fish consumption. Ourobjective in this study was to examine the relationshipsbetween RBC-Hg and plasma fatty acid composition inmother and fetus at parturition. Venous blood samples werecollected from 63 pairs of mothers and fetuses (umbilicalcord blood) at delivery. In all cases, fetal RBC-Hg levels werehigher than maternal RBC-Hg levels. The geometricmean of fetal RBC-Hg was 13.4 ng/g, which was significantly(p < 0.01) higher than that of maternal RBC-Hg (8.41ng/g). While the average fetal/maternal RBC-Hg ratio was1.6, the individual ratios varied from 1.08 to 2.19, suggesting considerable individual differences in MeHgconcentrations between maternal and fetal circulations atdelivery. A significant correlation was observed betweenmaternal and fetal DHA concentrations (r = 0.37, p < 0.01).Further, a significant correlation was observed betweenRBC-Hg and plasma DHA in fetus (r = 0.35, p < 0.01). Theseresults confirm that both MeHg and DHA which originatedfrom fish consumption transferred from maternal tofetal circulation and existed in the fetal circulation with apositive correlation. Pregnant women in particular neednot give up eating fish to obtain such benefits. However, theywould do well to at least consume smaller fish, whichcontains less MeHg, thereby balancing the risks andbenefits from fish consumption.