男性胎儿DNA含量低的孕妇的无创产前检测

目的探讨外周血中胎儿DNA含量低的孕妇的无创产前检测(NIPT)。方法回顾分析2015年4月至2016年3月间在佛山市妇幼保健院行NIPT的3 240例孕妇实验数据与随访资料,根据其Y染色体z值,筛选出胎儿为男性且胎儿DNA含量低于8%的样品共150例,利用琼脂糖凝胶电泳富集法提高胎儿DNA含量,进行NIPT,对比非整倍体筛查结果的准确率。结果琼脂糖凝胶电泳富集法将样品中的胎儿DNA含量从平均5%提高到9.2%。对比胎儿DNA含量提高前后的NIPT结果是一致的。结论当胎儿DNA含量高于5%时,胎儿DNA含量不会影响NIPT结果的准确率。

Influence of cell free fetal fraction DNA for noninvasive prenatal test

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% .