Coenzyme Q10 (CoQ10 or ubiquinone) is an essential component of the mitochondrial electron transport chain and is also present in various cellular membranes and in plasma lipoproteins. Diabetes, cardiovascular, neurodegenerative, and preeclampsia diseases are all associated with an alteration of CoQ10 level or its redox status. During pregnancy, we note that the plasma content of CoQ10 is significantly higher than amniotic. In the fetal growth restriction group, amniotic total CoQ10 levels were significantly higher versus healthy, while the amniotic oxygen radical absorbing capacity level was significantly lower. A significant negative correlation was observed between amniotic total CoQ10 and birthweight. Our observation leads to the hypothesis that the amniotic midtrimester CoQ10 content may be a marker of subsequent obstetric complications.