Abstract: Objective To investigate the correlation between CYP11A1 gene promter methylation and fetal growth restriction (FGR) and preeclampsia (PE).Methods The bisulfite pyrosequncing assay and qRT-PCR were used to demonstrate CYP11A1 methylation and expression patterns respectively in FGR, PE and FGR-PE, as well as Control associated placentas and cord blood of fetus.Results The promoter of CYP11A1 was found to be significantly hypomethylated in FGR, PE and FGR-PE placentas. And the methylation of CYP11A1 gene was relatively lower in FGR- PE than other case.Meanwhile the increased CYP11A1 expression was inversely modulate with CYP11A1 hypomethylation FGR, PE and FGR-PE placentas. which only found in placenta but not in cord blood of fetus.Conclusion As tissue-specific epigenetic marker of CYP11A1 gene, which was associated with fetal growth restriction and preeclampsia or both.

Key words: Key word: fetal growth restriction, preeclampsia, DNA methylation, placenta , CYP11A1, epigenetics