本研究的目的在探討母血篩檢唐氏症結果為陽性的孕婦在面對羊膜穿刺術的決策過程。以半結構式訪談法，訪談17位孕婦，並使用紮根理論研究法來分析資料。結果發現，個案共有四種決策型態，並依其過程進展，可分為三個階段：獲知檢查結果後過渡期、決策過渡期及決策後過渡期。大部分個案有驚訝、害怕、緊張、擔心、難過、及壓力等反應，個案於決策過渡期關心的事項包括：確定胎兒的健康、正常、與安全，害怕羊膜穿刺術會造成流產、釐清羊膜穿刺術與母血篩檢的關係、傾聽醫生或家庭成員的意見、及害怕胎兒不健康而必須做人工流產的手術等。個案於決策後過渡期關心的事項，則有羊膜穿刺術的相關訊息、胎兒檢查結果為異常時的處置、執行羊膜穿刺術地點的選擇、檢查前的準備、及決策時間的不足等。每一階段並有相對應的因應策略。

　　　　　The purpose of this study was to explore the decision-making process of pregnant women with positive reaction to maternal serum screening for Down's syndrome when facing amniocentesis. Seventeen pregnant women consented to participation in this study. The data were collected through semi-structured interviews and analyzed using the grounded theory method. The findings revealed that there were four decision-making patterns. Each pattern could be grouped into three stages: post-acknowledgement transition, decision-making transition, and after-decision transition. Most participants had psychological reactions, which included shock, fear, nervousness, worry, sadness, and stress. Their concerns during the decision-making transition stage were: confirmation of health, normality, and safety of the fetus, fear of abortion due to amniocentesis, clarification of relations between amniocentesis and maternal serum screening, opinions from physicians and family members, and fear of artificial abortion for unhealthy fetus. Concerns during the after-decision transition stage were: information relating to amniocentesis, the management of an abnormal fetus, the place for amniocentesis, preparation before amniocentesis, and inadequate time for making a decision. Coping strategies were deve-loped to deal with their concerns.