孕婦接受羊膜穿刺或非侵入性胎兒染色體篩檢抉擇動機及遺傳諮詢需求之探討

Abstract

現今產前診斷主要是以「羊膜穿刺術」或「絨毛膜取樣術」分析胎兒染色體為主，但上述均為侵入性檢查，孕婦必須承擔流產、感染、破水等微量風險（千分之一至千分之三），對於當今晚婚、晚產、少子化及接受不孕症治療比例增高的社會環境下，孕婦是否願意承擔這樣的風險仍值得探討。為因應社會需求，發展非侵入性且具高偵測率之篩檢或診斷技術是當今產前診斷重要的發展趨勢。 目前產前診斷技術除了羊膜穿刺術外，已發展非侵入性胎兒染色體篩檢 NIPT(Non-invasive Prenatal Test)，是由孕婦的血漿分離出一部份胎兒片段游離核苷酸，利用基因序列分析技術，進行染色體非整倍體分析，偵測出第21、18、13對染色體三倍體異常之疾病（最常見之染色體異常疾病），其偵測率可達99%，偽陽率小於0.1%，具高度敏感性和特異性。 本研究目的為瞭解孕婦接受羊膜穿刺或非侵入性胎兒染色體篩檢之抉擇動機，並分析介入遺傳諮詢後之成效。本研究於臺北市某婦產專科診所進行，研究對象為行羊膜穿刺術和行非侵入性胎兒染色體篩檢之孕婦共43位，其中行羊膜穿刺術者為23位，行非侵入性胎兒染色體篩檢者為20位，所收集之資料包括孕婦基本人口學特徵、影響抉擇因素、動機因素、對羊膜穿刺及非侵入性胎兒染色體篩檢知識瞭解程度，以及給予遺傳諮詢後之成效評估。 研究結果顯示:比較孕婦抉擇羊膜穿刺或非侵入性胎兒染色體篩檢之動機，發現孕婦決定行羊膜穿刺之主要原因依序為符合政府補助條件、年齡超過34歲、檢查費用考量；行非侵入性胎兒染色體篩檢之主要原因依序為無需承擔流產風險、此胎為試管嬰兒、醫師建議。 孕婦接受遺傳諮詢前後對羊膜穿刺及非侵入性胎兒染色體篩檢之知識量表得分有統計上高度顯著差異(p<.001)，顯示介入遺傳諮詢對羊膜穿刺及非侵入性胎兒染色體篩檢之知識瞭解程度有顯著幫助。孕婦接受遺傳諮詢後之成效亦有統計上顯著差異，顯示產前遺傳諮詢確實有其存在之必要性。

Amniocentesis and chorionic villus sampling are the main techniques of prenatal diagnosis. They are used to identify fetal chromosomal aneuploidies. The diagnosis of them is very accurate, but the invasive of which may cause intrauterine infection and abortion (0.1%~0.3%). Today the social phenomenon is late marriage, advanced maternal age, declining birthrate and rising the requirement of infertility treatment. The development of non-invasive prenatal diagnosis and high detection rate are very important in the future. NIPT (Non-invasive Prenatal Test) uses cell free fetal DNA from the plasma of pregnant women, and combines with new DNA sequencing technology. It has high sensitivity and specificity to common fetal trisomy 21 (Down syndrome, T21), trisomy 18 (Edwards syndrome, T18), trisomy 13 (Patau syndrome, T13). NIPT provides detection rates >99% and false-positive rates <0.1%. The study was aimed to discover the choice motivations affecting pregnant women’s acceptance of amniocentesis or NIPT, and the effectiveness of genetic counseling. 43 subjects were recruited using structured questionnaires at an obstetric clinic in Taipei. Among them, 23 women chose amniocentesis and 20 women chose NIPT. The structured questionnaire includes the demographic background, pregnancy experience, influencing factors, motive factors, and the knowledge scale of amniocentesis and NIPT. The results of the study were that comparing the motive factors about pregnant women’s accepting amniocentesis or NIPT. The pregnant women chose amniocentesis in the order of government subsidies, advanced maternal age, the cost of prenatal testing. Whereas, the pregnant women chose NIPT in the order of no miscarriage risk, test-tube baby, the suggestion of doctor. After genetic counseling, the scores of knowledge scale for amniocentesis and NIPT were increasing. It was significantly different (p<.001) in the groups. The study showed the genetic counseling had positive effect in rising cognition about amniocentesis and NIPT. The effectiveness of the genetic counseling was also significantly different. It showed the prenatal genetic counseling was necessary and helpful to pregnant women.