1026例孕中期妇女唐氏综合征和神经管缺陷的血清筛查及细胞染色体分析

目的：探讨孕中期妇女（14～20）周外周血甲胎蛋白（AFP）和游离绒毛膜促性腺激素（f-βHCG）在胎儿唐氏综合征（Down’s syndrome,DS）产前筛查中的作用。方法：应用免疫化学发光法分别检测1026例孕中期孕妇血清AFP和f-βHCG浓度,结合母龄、孕周和体重等因素,用筛查软件计算风险系数,对DS高危孕妇进行羊水细胞染色体核型分析,神经管缺陷（NTD）高危孕妇行B超检查。结果：筛查的1026例孕妇中,DS高危孕妇64例,阳性率6.2%,NTD高危孕妇9例,阳性率0.88%。在高危孕妇中发现4例胎儿染色体异常,1例经B超检查确诊为神经管畸形。两组异常胎儿染色体检出率有显著性差异（P〈0.01）,35岁或35岁以上孕妇组胎儿异常发生率高于35岁以下孕妇组（P〈0.01）。结论：利用DS筛查结合B超产前诊断,能够提高胎儿先天性缺陷的早期发现和诊断。

Screening with Serum Markers for Fetal Down's Syndrome and Neural Tube Defects During Second Trimester of Pregnancy Plus Amiotic Cell Chromosomal Studies in High Risk Cases

Objective To screen pregnant women during second trimester for potential fetal Down＇s syndrome and neural tube defect with serum markers AFP and free βHCG. Methods Serum AFP and free βHCG contents were determined with CLIA during second trimester in 1026 pregnant women. Amniocentesis with cell chromosomal studies was performed in cases designated as high risk with Down＇s syndrome and ultrasonic studies was performed in cases with potential fetal neural tube defects （NTD）. Results Among the 1026 pregnant women,64 （6.2%） were found to be at high risk with potential Down fetus and 9（0.88%） were at high risk with potential fetal NTD. Fourteen of the 64 women received amniocentesis and cell chromosomal study revealed 3 cases of Down＇s syndrome and 1 case of 18-trisomy. One case of hydrocephalus was confirmed with ultrasonography in the 9 potential cases of NTD. Three out of the four cases with proven chromosomal disorders were in pregnant women over 35 years old. Conclusion Screening with serum markers AFP and free β-HCG determination combined with amniotic cell chromosomal study and fetal ultrasonography would be very helpful for early diagnosis of fetal Down＇s syndrome and NTD.