N-3 and N-6 polyunsaturates, DHA (docosahexaenoic acid, 22:6n-3) and ARA (arachidonic acid, C20:4n-6), are important in perinatal development. In contrast, increased body burden of polychlorinated dibenzo-p-dioxins (PCDD/Fs) or polychlorinated dibenzofurans (PCBs) lead to impaired neurological development. Because of similar chemical properties and origins of food sources, critical delivery of DHA and ARA to the fetus may also contribute to increased exposures to lipophilic organo-chlorines. This study aimed to examine relationships between placental PCDD/Fs and PCBs toxic equivalent (TEQ) and DHA/ARA levels in 34 pregnant women from Taiwan. Trends of decreases in DHA (p=0.025) were observed as PCDF TEQ increased. Similarly, placental levels of ARA were reduced (p=0.020) as PCDF TEQ levels increased. In contrasts, DHA and ARA did not correlate with TEQ levels of PCDD or PCBs. After adjusting for confounders, increase in one PCDF TEQ were negatively correlated with decreases in 0.312% (wt%) of placental DHA (beta=–0.312, p=0.027) and 1.021% (wt%) of ARA (beta=–1.021, p=0.025). Thus, increases in body burden of PCDFs may alter placental DHA and ARA status. Mechanisms regarding placental DHA and ARA transfer which may be interfered by dioxin exposure warrant further investigation.
