孕早期预测胎儿性别，FSEB提出有效无创方法

　　

生物通报道  近期来自韩国关东大学医学院（KwanDong University School of Medicine）的研究人员在新研究中发现检测孕妇血浆中的两种酶DYS14与GAPDH的比值可实现早期有效预测胎儿的性别，该研究发现将有可能促使开发出一种新的非侵入式检测方法，使准妈妈们能够在孕期头三个月即可知晓胎儿的性别。这种测试技术将开启无创产前检测胎儿性别检测的先河。相关研究成果发表在2012年1月版的《FASEB》杂志上。

胎儿性别是许多准爸爸妈妈特别关心的问题，猜测肚子的宝宝是男是女也是大家的乐趣。关于这一点，国内民间有许多种说法，比如肚子形状，孕妇口味等等。从医学的角度而言，判断胎儿的性别主要是通过超声波检查，最早在妊娠11周时就可以通过影像判断，但是这种方法并不一定精准。羊膜穿刺术会，以及绒毛采检术也是医学鉴别方法，然而这些方法有可能会导致流产，或者伤害胎儿，因此一般不建议使用。

“目前临床上通常采用的是侵入性的检测技术例如绒毛膜绒毛取样或羊膜穿刺术来进行早期胎儿性别检测。然而这些侵入性的检测方法仍然可导致1-2%的流产风险，且需要到妊娠第11周时才能开展。利用超声则无法在孕期头三个月进行可靠的胎儿性别鉴定，这是由于此时胎儿的外生殖器发育尚不完全，”韩国关东大学医学院女性健康照护医院（Cheil General Hospital and Women's Healthcare Center）妇产科研究人员Hyun Mee Ryu博士说。

为了获得这一研究发现，Ryu及同事们收集了203名妇女在怀孕前三个月时的血浆样本。利用U-PDE9A定量甲基化特异性聚合酶链式反应对血浆中的胎儿DNA进行了检测。同时利用多重实时聚合酶链式反应对孕妇血浆中的DYS14和GAPDH进行了定量分析。这些试验结果在出生时性别分型时得到了验证。

“尽管在该测试获得广泛临床应用前，还有大量的工作需要开展。新研究表明有可能实现在受孕后的前几周即预测出孩子的性别，”FASEB杂志首席主编Gerald Weissmann说：“当前的技术有时会使得准父母获得未出生孩子的错误信息，这一检测将有助于解决当前超声检测的不确定性。”

（生物通：何嫱）

延伸阅读：Nature：无创产前诊断时代的到来

生物通推荐原文摘要：

Effective detection of fetal sex using circulating fetal DNA in first-trimester maternal plasma

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% for DYS14 concentration, and 0.0% for the concentration ratio of DYS14/GAPDH, respectively. In male-bearing participants, DYS14, U-PDE9A, and GAPDH concentrations 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.