Maternal serum mitochondrial DNA (mtDNA) levels are elevated in preeclampsia - A matched case-control study

Oxidative stress and mitochondrial dysfunction may play a crucial role in preeclampsia (PE). The aim of this study was to investigate differences in maternal levels of serum-mitochondrial (mt) DNA, a proposed biomarker for mitochondrial dysfunction, in women with PE compared to healthy pregnant women.

Using samples obtained from the prospective Biobank study, we measured serum-mtDNA levels in pregnant women diagnosed with PE and in women with uneventful pregnancies, matched for gestational and maternal age, BMI, and smoking status. In a second step, we performed a generalized linear model to detect associations between mtDNA-serum-levels and certain conditions during pregnancy.

Mean mtDNA levels were significantly higher in PE (n = 20) than in matched controls (n = 20) and were 0.00767 (SD 0.00255) U/L and 0.00513 (SD 0.00458) U/L, respectively (p = 0.038). We did not find a significant correlation between higher mtDNA levels and early onset PE, IUGR, maternal age, or maternal BMI. Interestingly, increased mtDNA levels were significantly associated with female fetal sex (p = 0.003).

Our findings strengthen the hypothesis postulating that oxidative stress and mitochondrial dysfunction are key factors in the pathophysiology of PE. More prospective studies are highly warranted to further investigate the role of mtDNA in PE and assess the usefulness as a possible biomarker for PE.