Objective: To evaluate the efficiency of cell-free fetal DNA detection as a non-invasive prenatal screening (NIPS) method for women of advanced maternal age.
Methods: A total of 10 584 women of advanced maternal age who received NIPS were recruited from the Women's Hospital, Zhejiang University School of Medicine and Jiaxing Maternal and Child Health Hospital during February 2015 and September 2016. The pregnancy outcome was followed-up. The sensitivity, specificity, positive and negative predictive value of fetal chromosomal aneuploidy detected in NIPS were analyzed. And the relationship between maternal age and fetal common chromosomal aneuploidy was analyzed.
Results: The sensitivity, specificity, positive and negative predictive value of NIPS were 100.00%, 99.96%, 91.67%, 100.00% for trisomy 21, 100.00%, 99.93%, 68.18%, 100.00% for trisomy 18, and 100.00%, 99.97%, 25.00%, 100.00% for trisomy 13. High-risk rate and true positive rate of trisomy 21 were positively correlated with the maternal age (all P<0.01). There were significant differences in high-risk rate and true positive rate between 35-37 year old groups and 38-40 year old groups (all P<0.05). Such difference was also found in high-risk rate between 38-40 year old group and ≥ 41 year old group (P<0.05), but not in true positive rate between two groups (P>0.05).
Conclusions: NIPS is effective for fetal chromosomal aneuploidy screening in women of advanced maternal age. For women under 38 years of age, NIPS is preferred; for women of 41 and above, invasive diagnostic methods are suggested; and for women between 38-41 years old, the option can be determined by themselves after risks and advantages were fully informed.
目的: 评估孕妇外周血胎儿游离DNA检测这一无创产前筛查（NIPS）技术在高龄孕妇产前筛查中的效率，并据此提出高龄孕妇产前筛查及诊断的优化策略。
方法: 以2015年2月至2016年9月在浙江大学医学院附属妇产科医院和嘉兴市妇幼保健院行NIPS并完成妊娠结局随访的10 584名高龄孕妇为研究对象，统计NIPS在高龄孕妇中检测胎儿常见染色体非整倍体的敏感度、特异度、阳性预测值和阴性预测值，并分析孕妇年龄与胎儿常见染色体非整倍体疾病的相关性。
结果: NIPS检测高龄孕妇胎儿21三体的敏感度为100.00%、特异度为99.96%、阳性预测值为91.67%、阴性预测值为100.00%；检测18三体的敏感度为100.00%、特异度为99.93%、阳性预测值为68.18%、阴性预测值为100.00%；检测13三体的敏感度为100.00%、特异度为99.97%、阳性预测值为25.00%、阴性预测值为100.00%。胎儿21三体的高风险率和真阳性率随孕妇年龄的增长而升高（均 P < 0.01）。其中，35~37岁组与38~40岁组21三体的高风险率和真阳性率差异有统计学意义（均 P < 0.05）；38~40岁组与41岁以上年龄组21三体的高风险率差异有统计学意义（ P < 0.05），但真阳性率差异无统计学意义（ P>0.05）。
结论: NIPS用于高龄孕妇的产前筛查具有良好的检测效率。对于预产期年龄38岁以下的孕妇，NIPS可作为优先选项；对于预产期年龄超过41岁的孕妇，建议选择介入性产前诊断；而对于预产期年龄为38~ < 41岁的孕妇，则可充分告知后酌情选择。