发表在FASEB杂志2012年1月刊上的一篇研究，为我们描绘了一种安全无害的、在孕期头三个月就能检测出胎儿性别的新方法。具体来说，韩国研究人员发现可以通过测定孕妇血液中两种酶的比率（DYS14/GAPDH）来预测肚子里的是男宝宝还是女宝宝。这项测试将会成为这种检测的第一步。
“在此之前，早期胎儿性别测定所采用的方法大多对人体有害，比如绒毛膜绒毛取样、羊膜腔穿刺术等，这些方法会增加1%~2%的流产风险，而且必须在怀孕11周后才能进行。再者，口碑颇好的超声波检查法鉴定胎儿性别在怀孕头三个月也不能实施，因为那时候胎儿的性别特征还不明显。所以，这种方法的出现，可以有效地减少由上述有害检测方法所引起的孕妇X-连锁染色体异常，能显示出超声波所无法检测出的结果。”研究者之一、来自Cheil General Hospital妇产科的Hyun Mee Ryu博士说。
在研究期间，Ryu和他的同事采集了203位处于头三个月孕期的妇女的血液。利用特异性甲基化的U-PDE9A聚合酶链式反应对妈妈血液中存在的胎儿DNA进行定量检测。同时，研究者们还利用多元、实时聚合酶链式反应对妈妈血液中的DYS14和GAPDH的含量进行了测定。等到宝宝们出生以后，再将所预测结果与之进行比对。
“尽管如此，要想将该项研究真正应用于临床，还有很多工作要去完成。而且论文中也未提及这项技术可以早到在怀孕几周后就能检测出胎儿的性别。目前，有时候家长会被告知错误的、关于其未出生宝宝的性别信息，而这项研究已被证实能为解决超声波观察无法确定的因素提供强有力的帮助。”FASEB杂志的总编辑、医学博士Gerald Weissmann如是说。
Effective detection of fetal sex using circulating fetal DNA in first-trimester maternal plasma
Ji Hyae Lim, So Yeon Park, Shin Young Kim, Do Jin Kim, Ji Eun Choi, Min Hyoung Kim, Jun Seek Choi, Moon Young Kim, Jae Hyug Yang and Hyun Mee Ryu
The aim of this study was to develop a simple and effective method for noninvasively detecting fetal sex using circulating fetal DNA from first-trimester maternal plasma. A study was conducted with maternal plasma collected from 203 women between 5 and 12 wk of gestation. The presence of circulating fetal DNA was confirmed by a quantitative methylation-specific polymerase chain reaction of the unmethylated-PDE9A gene (U-PDE9A). Multiplex real-time PCR was used to simultaneously quantify the amount of DYS14 and GAPDH in maternal plasma. The results were confirmed by phenotype at birth. Pregnancy outcomes and U-PDE9A concentrations were obtained in all cases, including 99 male-bearing and 104 female-bearing participants. At equivalent specificity (100%), the false-negative rate was 9.1% for DYS14 quantification cycle, 7.1% forDYS14 concentration, and 0.0% for the concentration ratio of DYS14/GAPDH, respectively. In male-bearing participants, DYS14, U-PDE9A, and GAPDHconcentrations were significantly lower in the false-negative case than in correct case (P<0.001 in all). Moreover, DYS14, U-PDE9A, and GAPDH concentrations showed significantly positive associations with each other (P≤0.001 in all). The ratio of DYS14/GAPDH in maternal plasma was an effective biomarker for noninvasive fetal sex detection during the first trimester, indicating that it could be useful for clinical application.—Lim, J. H., Park, S. Y., Kim, S. Y., Kim, D. J., Choi, J. E., Kim, M. H., Choi, J. S., Kim, M. Y., Yang, J. H., Ryu, H. M. Effective detection of fetal sex using circulating fetal DNA in first-trimester maternal plasma.
