在法国,产前筛查21-三体,最主要的特点是所有年龄38岁和曾有染色体异常儿生育史的妊娠妇女都需做胎儿染色体核型分析。从1997年以来,妊娠中期母血清标记物(MSM)筛查高危和妊娠11～14周胎儿颈项半透明区(NT)增厚的妊娠妇女也需进行胎儿染色体核型分析。此外,妊娠20～22周和32周 In France, prenatal screening of 21-trisomy, the most important feature of all 38-year-old pregnant women who have had a history of chromosomal abnormalities are required fetal karyotype analysis. Since 1997, fetal chromosomal karyotyping has also been performed in pregnant women at high risk of screening for a second trimester maternal serum marker (MSM) and thickening of the fetal neck translucency (NT) area between 11 and 14 weeks of gestation. In addition, 20 to 22 weeks of gestation and 32 weeks of gestation