RESUMO
Objective To explore the influence of lower concentration of cell free fetal fraction DNA in maternal plasma on non-invasive prenatal test(NIPT) .Methods A total of 3240 pregnant women accepted NIPT in Foshan Maternal and Children′s Hos-pital from April ,2015 to March ,2016 were analyzed retrospectively ,and 150 samples of which were male fetus judged by Z score of Y chromosome and the cell free fetal fraction DNA were lower than 8% were selected .The cell free fetal fraction DNA were in-creased by agarose gel electrophoresis ,then conducted NIPT ,compared with the results of aneuploidy screening .Results The cell free fetal fraction DNA were increased from 5% to 9 .2% by agarose gel electrophoresis .The result of NIPT after increasing fetal fraction was consistent with it before .Conclusion Concentration of cell free fetal fraction DNA has no influence on the result of NIPT when cell free fetal fraction DNA is above 5% .
RESUMO
Objective To explore the influence of lower concentration of cell free fetal fraction DNA in maternal plasma on non-invasive prenatal test(NIPT) .Methods A total of 3240 pregnant women accepted NIPT in Foshan Maternal and Children′s Hos-pital from April ,2015 to March ,2016 were analyzed retrospectively ,and 150 samples of which were male fetus judged by Z score of Y chromosome and the cell free fetal fraction DNA were lower than 8% were selected .The cell free fetal fraction DNA were in-creased by agarose gel electrophoresis ,then conducted NIPT ,compared with the results of aneuploidy screening .Results The cell free fetal fraction DNA were increased from 5% to 9 .2% by agarose gel electrophoresis .The result of NIPT after increasing fetal fraction was consistent with it before .Conclusion Concentration of cell free fetal fraction DNA has no influence on the result of NIPT when cell free fetal fraction DNA is above 5% .