本研究的目的在於瞭解國內婦女子宮外孕的發生比例及其危險因子。選擇85名子 宮外孕的婦女為病例組，並以 1：2 的比例取年相距三歲以內並完成一次生產的婦女為對照 組，進行以醫院為基底之病例對照研究。以病歷摘錄法為主要資料收集法。結果發現，子宮 外孕的平均發生比例是 1：44。 以年齡 20-29 歲，30-39 歲，40-44 歲分層，其發生比例 分別是 1：67，1：23，1：6。 以單變項統計，有顯著差異的危險因子，包括：婚姻狀態、 教育程度、孕次、產次、流產次、子宮內避孕器、口服避孕藥、輸卵管結紮、骨盆腔發炎、 骨盆腔手術、抽煙。以多變頸對數複迴歸分析得到的重要危險因子則是有無骨盆腔發炎和有 無裝置子宮內避孕器，其多變項調整對比值分別是 28.84 和 5.10。

　　　　　To evaluate the assoication between ectopic pregnancy and potential risk factors, we conducted a hospital-based case-control study. The investigation including 85 cases was diagnosised from January to December, 1992, by laparotomy, and 95 matched controlls selected from live-birth deliveries. Risk factors information was obtained via the abstract of medical records. The ratio of ectopic pregnancy to deliveries was 1 to 44. The ratios by age of 20-29,30-39,40-44, are 1 to 67,1 to 23, and 1 to 6 respectively. Univariate matched analyses reveal 11 variables associated with a significantly elevated relative risk of ectopic pregnancy. According to following multiple logistic regression, there are two variables remained as stronged independent risk factors for ectopic pregnancy, which are a history of pelvic inflammatory disease(relative risk 28.84) and intrauterine device use (relative risk 5.10).