羊膜穿刺與染色體異常個案之分析（2006~2015年）

Analysis of Amniocentesis and Cases of Chromosomal Abnormalities (2006~2015)

產前的篩檢項目中，染色體檢查是相當重要的一項，尤其是高齡產婦或是流產高發生群孕婦。根據統計的結果，一般產前胎兒中約有2%會發生染色體異常症，而異常的染色體往往會造成胎兒各式各樣的先天畸形，甚至造成習慣性的流產或不明原因的流產。進一步了解，約有50%-60%的流產胎兒，是因為染色體上的異常導致。鑒於此，為避免染色體異常的小孩出生造成家庭及社會的雙重負擔，國民健康署鼓勵高危險群孕婦應該進行產前診斷，經由採檢胎兒的絨毛或抽取羊水，可進行染色體分析，確保胎兒的正常。因此產前羊水染色體（chromosome）分析策略，是一項極具意義之預防醫學工作。本篇研究以送檢樣本結果異常案例為主要討論對象，其目的在於藉由羊水染色體的分析，來探討染色體異常與危險因子之相關聯性。
本研究取樣共2011例，對象是在秀傳紀念醫院做羊膜穿刺術染色體檢查之孕婦，時間從2006至2015年，其全部染色體異常率為1.69%，1994年再加上唐氏母血篩檢，平均異常率則從1.52%提高至1.69%，對於多種染色體異常比率的發現也有明顯的改變，而其中對觀察Trisomy 21及性染色體及轉位染色體異常更有明顯的幫助，而由染色體異常個案追蹤中，發現數目異常現象者，通常是精子或卵子減數分裂不分離所造成，而結構異常者通常都是遺傳自父親或母親。希望這些數據可以在產前優生保健及遺傳諮詢方面，提供臨床醫師更多的本土資訊。

In prenatal screening programs, chromosome examination is important, especially for groups with advanced maternal age and high incidence of maternal abortion. According to results of statistics, generally, 2% of fetuses have chromosome abnormalities and abnormal chromosomes usually lead to different kinds of congenital malformations, and even habitual abortion or unexplained miscarriages. Further, about 50%-60% of aborted fetuses are caused by chromosome abnormalities. In view of this, to avoid cases of children with chromosome abnormalities, along with the resulting burden on families and society, the Health Promotion Administration encourages high-risk groups of pregnant women to seek prenatal diagnoses by collecting fetal villi or extracting amniotic fluid to conduct chromosome analysis to determine normal fetuses. Therefore, prenatal chromosome analysis of amniotic fluid is a meaningful preventive service task. The purpose for our research is to discover the relationship between the risk factors and chromosome anomalies by examining abnormal cases using amniotic fluid chromosome analysis.
This research is based on the analysis of amniocentesis data from Chanhua Show Chwan Memorial Hospital. Tracing back the data of the abnormal cases, we can discover the relationship between risk factors and chromosome anomalies. The duration of our amniocentesis research was from 2006 to 2015. During this period, 2011 pregnant women accepted amniocentesis in our hospital. The total abnormality rate of chromosome study for amniocentesis cases was 1.69 %. Since 1994, Down screening of maternal blood has been introduced in the obstetric clinics in our hospital. The average detection rate of amniocentesis in fetal chromosome abnormalities has increased from 1.52% to 1.69%. Chromosome abnormalities have been noted to result in prominent change, especially in Trisomy 21, the sexual chromosome and translocation chromosome abnormalities. Generally, the abnormal number of chromosomes occurs in the stage of meiosis. The structural abnormality of chromosomes is related to the parent origin.
We hope our data can provide more information for obstetric clinic doctors, enhance eugenic knowledge and serve as a reference during prenatal genetic consultations. The results also can contribute to the database in Taiwan.