Maternal xenobiotic metabolism

Maternal xenobiotic metabolism plays an important role in determining how much xenobiotic reaches the embryo and fetus, and hence can modulate developmental toxicity due to either receptor- or reactive intermediate-mediated mechanisms. For example, pregnant Gunn rats with low UGT activity exhibit decreased glucuronidation of benzo[a]pyrene metabolites and a three-fold increase in fetal resorptions (in utero death) (Wells et al. 2004). 

Pregnant females have a reduced ability to metabolize xenobiotics. This is so because of the reduced activity of a large number of maternal enzymes during pregnancy. Accordingly, it is particularly important that pregnant women avoid exposures to toxic chemicals as much as possible. 

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