探讨妊娠期胎儿染色体核型异常的产前诊断指征，为产前诊断及遗传咨询提供参考依据。

收集2010年10月至2014年4月于甘肃省妇幼保健院产前诊断中心接受介入性产前诊断胎儿染色体核型分析的5 655例孕妇的临床病历资料为研究对象。其产前诊断指征包括：产前血清学筛查结果高风险，如21-三体综合征风险值≥1/270或18-三体综合征风险值≥1/350(2 482例)，高龄(年龄≥35岁，1 889例)，不良妊娠史(675例)，夫妇一方染色体异常(49例)，产前超声检查结果异常(465例)，以及早孕期接触大量化学毒剂、辐射或严重病毒感染，或服用可能致畸的药物等(95例)，上述产前诊断指征均为单一指征，无交叉。通过羊膜腔穿刺染色体检查进行胎儿染色体核型异常确诊。采用回顾性分析法对上述具有不同产前诊断指征孕妇的临床病历资料，进行胎儿染色体核型异常类别及检出例数、检出率，以及产前超声检查结果异常与胎儿染色体核型异常结果进行分析，并对具有不同产前诊断指征孕妇的胎儿染色体核型异常检出率，进行统计学分析。本研究遵循的程序符合本院人体试验委员会所制定的伦理学标准，得到该委员会的批准，介入性产前诊断术前均与受试者签署知情同意书。

①接受介入性产前诊断的5 655例孕妇中，共计检出胎儿染色体核型异常为124例，检出率为2.2%。分别以产前血清学筛查结果高风险、高龄、不良妊娠史、夫妇一方染色体异常、产前超声检查结果异常、早孕期异常物质接触史为产前诊断指征，进行介入性产前诊断的孕妇分别为2 482、1 889、675、49、465及95例，检出胎儿染色体核型异常分别为40、47、12、5、19及1例，检出率分别为1.6%、2.5%、1.8%、10.2%、4.1%及1.1%。夫妇一方染色体异常及产前超声检查异常孕妇胎儿的染色体核型异常发生率较高。上述具有不同产前诊断指征孕妇的胎儿染色体核型异常检出率比较，差异有统计学意义(χ²＝28.23，P<0.001)。②以产前超声检查结果异常为产前诊断指征，检出19例染色体核型异常胎儿中，具有结构明显异常者为6例，包括心脏畸形、全身水肿等；仅超声软指标异常者为13例，包括心室强光点、肾盂分离、脉络丛囊肿、单脐动脉、肝内强光点、颈项透明层(NT)增厚、羊水量异常，以及胎儿生长指标(头围、双顶径、股骨及肱骨长)异常与鼻骨缺失和侧脑室正常高值等。

产前超声检查结果发现胎儿存在畸形或2项及以上超声软指标异常时，有必要对胎儿进行染色体核型分析。

To study the indications of prenatal diagnosis of fetal chromosome karyotype abnormalities, and provide the basis for prenatal diagnosis and clinical genetic counseling.

From October 2010 to April 2014, a total of 5 655 cases of pregnant women who received prenatal diagnosis of fetal karyotype analysis in Prenatal Diagnosis Center, Gansu Provincial Maternity and Child-care Hospital were selected as research subjects. The indications of prenatal diagnosis of the 5 655 cases of pregnant women contained high-risk indications of antenatal serological screening, such as trisomy 21 syndrome risk≥1/270 or trisomy 18 syndrome risk≥1/350 (2 482 cases), age≥35 years old (1 889 cases), adverse pregnancy history (675 cases), chromosomal abnormalities of one of the couple (49 cases), prenatal ultrasound abnormalities (465 cases), and exposure to the poisonous and harmful substance, drugs that may cause teratogenicity and radical line (95 cases). All the indications of prenatal diagnosis were uncrossed. Fetal chromosome karyotype abnormalities were diagnosed by amniocentesis. Different kinds of fetal chromosomes karyotype abnormalities, the number and detection rate, the relationship between fetal chromosome karyotype abnormalities and prenatal ultrasound abnormalities were analyzed by retrospective method. And the fetal chromosomes karyotype abnormalities detection rates of different indications of prenatal diagnosis were analyzed by statistical methods. The study protocol was approved by the Ethical Review Board of Investigation in Gansu Provincial Maternity and Child-care Hospital. Informed consent was obtained from each patient before receiving invasive prenatal diagnosis.

①Among the 5 655 cases of pregnant women who received invasive prenatal diagnosis, 124 cases were detected as fetal chromosomal karyotype abnormalities, and the detection rate was 2.2%. Among 2 482 cases of pregnant women with high-risk indications, 1 889 cases with age≥35 years old, 675 cases with adverse pregnancy history, 49 cases with chromosomal abnormalities of one of the couple, 465 cases with prenatal ultrasound abnormalities, 95 cases with exposure to abnormal substance, 40 cases, 47 cases, 12 cases, 5 cases, 19 cases, and 1 case were detected as fetal chromosomal karyotype abnormalities, respectively. And the the detection rate of fetal chromosomal karyotype abnormalities was 1.6%, 2.5%, 1.8%, 10.2%, 4.1% and 1.1%, respectively. The rate of fetal chromosomal karyotype abnormalities in pregnant women with chromosomal abnormalities of one of the couple or prenatal ultrasound abnormalities was high. There was statistical difference among the fetal chromosomes karyotype abnormalities detection rate of different indications of prenatal diagnosis (χ²=28.23, P<0.001). ②Among the 19 cases of fetal chromosomes karyotype abnormalities with prenatal ultrasound abnormalities, 6 cases were with obvious structural abnormalities, such as heart abnormalities and anasarca, 13 cases were only with soft ultrasound abnormalities, such as ventricular light point, pyelic separation, choroid plexus cysts, single umbilical artery, liver light point, increased thickness of nuchal translucency (NT), polyhydramnios or oligohydramnios, growth index (head circumference, biparietal diameter, length of femur and humerus) abnormalities, nasal bone absence, lateral ventricle normal high value and so on.

It is necessary for pregnant women to receive the fetal chromosomal karyotype analysis if there is malformation or two or more ultrasound soft markers abnormal of fetal ultrasound screening system.