目的　探讨孕中期唐氏综合征（DS）等筛查对检出胎儿出生缺陷和不良妊娠结局的实用价值。方法 用时间分辨荧光分析法对日照市7076名15~20孕周孕妇的血清甲胎蛋白（AFP）和游离绒毛膜促性腺激素（F-βHCG）进行检测，结合孕妇年龄、体重、孕周等因素，利用配套孕期胎儿唐氏综合征产前筛查分析软件，分析胎儿患DS、开放性神经管缺陷（NTD）、18-三体综合征的发病风险率，并对高风险孕妇行羊水胎儿细胞染色体核型分析或B超跟踪检查。结果　7076名孕妇中筛出高风险孕妇396例，阳性率为5.6%，在接受羊水检查的56名DS高风险孕妇中，检出唐氏胎儿3例，死胎3例，其它异常3例；对57例神经管缺陷髙危孕妇进行B超检查，发现1例无脑儿；在43例18—三体高危的孕妇中，6例做羊水染色体检查，结果均正常。结论 孕中期以唐氏综合征（DS）产前筛查作为对胎儿先天缺陷，尤其是胎儿染色体异常的筛查是行之有效方法，筛查结果呈高危孕妇须进行羊水染色体核型分析或B超检查。

Objective To explore the practical value of Down’s syndrome (DS) screening in detecting congenital birth defects and predicting adverse pregnancy outcomes among pregnant women at middle gestation. Methods The serum levels of F-βHCG and AFP in 7076 pregnant women at mid-term gestation of 15-20 weeks were detected by time resolved fluoroisnmunoassay. The corresponding simulation software was utilized considering the factors of gestational weeks, avoirdupois age and weight of pregnant women and etc to calculate the risk rates of fetuses with DS, Neural tube defects (NTD) and Trisomy 18. Karyotype analysis of amniotic fluid cells or B ultrasound examination for follow-up investigations was used for the high risk pregnant women. Results The positive cases among 7076 pregnant women screened were 396 and the positive rate was 5.6%. Among 56 cases of DS pregnant women with voluntary acceptance of amniotic fluid examination, 3 cases of DS and 3 cases of fetal deaths and 3 cases of other congenital anomalies were found. Among the 57 pregnant women with NTD 1 cases no brains was detected by B ultrasound examination. Among 43 case of pregnant women at high risk for trisomy 18, 6 cases accepted karyotype analysis of amniotic fluid cells examination and all results were normal. Conclusion Prenatal screening of detecting serum levels of F-βHCG and AFP at mid-gestation is a beneficial, effective and convenient method for screening the congenital defects, especially the fetal chromosomal abnormalities. The high risk pregnant women should carry out the karyotype analysis of amniotic fluid cells or B ultrasound examination further in order to reduce birth defects of fetus.