孕周和孕妇年龄对唐氏综合征筛查影响的回顾性研究

Retrospective study on the effects of gestational week and maternal age on screening of Down's syndrome

目的：探讨孕周及孕妇年龄在唐氏综合征筛查中的影响。方法：回顾性分析天津市2010年在孕中期进行产前筛查的孕妇血清标志物检测的结果，追踪2l一三体综合征高风险孕妇羊水细胞染色体检查的结果，比较相同年龄段孕妇不同孕周筛查唐氏综合征检出的假阳性率，并比较不同年龄段孕妇唐氏综合征筛查的高风险率。结果：在84401例受检孕妇中，共筛查出唐氏综合征高风险者3652例，确诊唐氏综合征者13例，筛查假阳性率为4．31％，其中孕17—18＋6周筛查的假阳性率〈4％（3．85％～3．98％），显著低于孕15～16＋6周、孕19～20＋6周的假阳性率（P〈0．05）；各年龄组孕妇之间检出唐氏综合征高风险率差异均有统计学意义（P〈0．01）。结论：应用血清学筛查方法和产前诊断技术在产前可有效检出唐氏综合征患儿，降低其出生率，为了提高唐氏综合征的检出率，建议进行产前筛查的理想孕周在17～18’6周。

Objective： To explore the effects of gestational week and maternal age on screening of Down＇s syndrome. Methods： The detection results of serum markers in pregnant women who received prenatal screening during the second trimester of pregnancy in Tianjin city in 2010 were analyzed retrospectively, the results of amniotic fluid cell chromosomal examination in pregnant women with high risk of tri- somy 21 were traced, the false positive rates of Down＇s syndrome were compared among different gestational weeks in pregnant women in the same age group, the high risk rates of Down＇s syndrome screening among pregnant women in different age groups were also compared. Re- suits： Among 84 401 pregnant women, 3 652 pregnant women were found with high risk of Downg syndrome, and 13 pregnant women were diagnosed as Down＇s syndrome definitely, the false positive rate of screening was 4. 31%, the false positive rate of screening in pregnant women of 17 - 18 ＋6 gestational weeks was less than 4% （3.85% -3.98% ） , which was statistically significantly lower than those in preg- nant women of 15 - 16 ＋6 gestational weeks and 19 - 20 ＋6 gestational weeks （ P 〈 0. 05 ） ; there was statistically significant difference in the high risk rate of Down＇s syndrome among pregnant women in different age groups （ P 〈 0. 01 ） . Conclusion： Serological screening and pre- natal diagnostic techniques can effectively detect the fetuses with Down＇s syndrome before delivery, reduce the birth rate of infants with Down＇s syndrome; in order to improve the detection rate of Downb syndrome, the ideal gestational weeks to conduct prenatal screening are 17 - 18 ＋6 gestational weeks.