Placental transport of dioxins from mother to fetus. II. PCBs, dioxins and furans and vitamin K metabolism.

Placental transport of dioxins and furans from mother to fetus takes place. It is probably related to the fatty acid transport. Between 10 and 20% of fatty acids in a full-term baby are of maternal origin. In adipose tissue of children that died in the early neonatal period concentrations of +/- 25% were found of three dioxin and furan congeners 12378 P5CDD, 123678 H6CDD, and 23478 P5CDF in relation to a mean concentration of these congeners in the fat of 14 breastmilk samples. Data of concentrations are given as measured in liver and adipose tissue. In the placenta of a Dutch woman an accumulation of dioxins and furans is found in relation to blood. Animal studies support the hypothesis that polychlorobifenyls play a role in the cause of the late hemorrhagic disease in the newborn, in particular the 2, 4, 5, 2, 4, 5-hexachlorobifenyl that is present in relatively high concentrations in breastmilk.