Maternal blood mitochondrial DNA content during normal and intrauterine growth restricted (IUGR) pregnancy

OBJECTIVE: We investigated mitochondrial DNA (mtDNA) content in the maternal circulation of normal pregnancies of different gestational ages and in pregnancies complicated by intrauterine growth restriction (IUGR). STUDY DESIGN: We examined 70 maternal blood samples: 13 nonpregnant women; 45 normal pregnancies, divided into the 3 trimesters; and 12 pregnancies complicated by IUGR. MtDNA content was determined by real-time quantitative polymerase chain reaction, using a genomic control and a target gene. RESULTS: A highly significant progressive reduction in circulating mtDNA was observed in pregnant women of first, second, and third trimesters and compared to nonpregnant women (mean value: 237, 188, 144, and 283, respectively; P .001). Moreover, mtDNA was significantly increased in women carrying IUGR fetuses compared to women with normal pregnancies (430 vs 144; P .001). CONCLUSION: MtDNA could provide new insight into the mechanisms that occur during physiological gestation. Furthermore, mtDNA content may help recognize the IUGR disease in pregnancy.