Vivanti Alexandre, Benachi Alexandra, Huchet François-Xavier, Ville Yves, Cohen Henri, Costa Jean-Marc
Service de Gynécologie-Obstétrique et Médecine de la Reproduction, Hôpital Antoine Béclère, Université Paris Sud, Clamart, France.
Laboratoire de Biologie Médicale, Paris, France.
Am J Obstet Gynecol. 2016 Nov;215(5):606.e1-606.e5. doi: 10.1016/j.ajog.2016.06.054. Epub 2016 Jul 5.
Rhesus D genotyping with cell-free fetal DNA currently is used throughout the world. Although this technique has spread rapidly, its optimal use is still a matter of debate. This screening test has been introduced mainly for the treatment of RhD-negative pregnant women during the third trimester of pregnancy, thereby avoiding systematic anti-D prophylaxis, yet such a strategy has proved cost-ineffective. Publications reporting on fetal RHD genotyping with cell-free DNA in maternal plasma, specifically during the first trimester of pregnancy, are scarce in the scientific literature.
This study sought to assess the performance of noninvasive fetal Rhesus D genotyping in the first trimester of pregnancy with a single-exon real-time polymerase chain reaction assay.
This was a retrospective observational multicenter study. Cell-free fetal DNA was extracted from maternal blood of both nonimmunized and immunized women at 10-14 weeks of gestation. RHD sequence was determined by quantitative polymerase chain reaction, with amplification of exon 10. Results were compared with RhD phenotype data that were obtained by cord blood sampling of neonates.
In total, 416 serum samples from RhD-negative pregnant women were collected during the first trimester of pregnancy. The test's overall sensitivity and specificity were 100% (95% confidence interval, 96.9-100.0) and 95.2% (95% confidence interval, 90.5-97.6), respectively. The negative and positive predictive values were 99.8% (95% confidence interval, 94.9-100.0) and 97.1% (95% confidence interval, 94.2-98.6), respectively. Fetal RHD status was inconclusive in 9 cases (2.2%).
Noninvasive fetal RHD determination by single-exon quantitative polymerase chain reaction during the first trimester of pregnancy exhibits high accuracy.
目前，利用游离胎儿DNA进行恒河猴D血型基因分型在全球范围内得到应用。尽管这项技术迅速普及，但其最佳应用仍存在争议。这项筛查试验主要是为了在妊娠晚期治疗RhD阴性孕妇，从而避免系统性抗D预防，但事实证明这种策略成本效益不佳。在科学文献中，关于利用母体血浆中的游离DNA进行胎儿RHD基因分型的报道，尤其是在妊娠早期的报道很少。
本研究旨在通过单外显子实时聚合酶链反应分析评估妊娠早期非侵入性胎儿恒河猴D血型基因分型的性能。
这是一项回顾性观察性多中心研究。在妊娠10 - 14周时，从未免疫和已免疫妇女的母血中提取游离胎儿DNA。通过定量聚合酶链反应测定RHD序列，扩增外显子10。将结果与通过新生儿脐带血采样获得的RhD表型数据进行比较。
总共在妊娠早期收集了416例RhD阴性孕妇的血清样本。该检测的总体敏感性和特异性分别为100%（95%置信区间，96.9 - 100.0）和95.2%（95%置信区间，90.5 - 97.6）。阴性和阳性预测值分别为99.8%（95%置信区间，94.9 - 100.0）和97.1%（95%置信区间，94.2 - 98.6）。9例（2.2%）胎儿RHD状态不确定。
妊娠早期通过单外显子定量聚合酶链反应进行非侵入性胎儿RHD测定具有很高的准确性。
