Professor Ko Tsang-ming, of the Department of Obstetrics and Gynecology at National Taiwan University Hospital, says that the CVS method of collecting fetal cell tissue for examination was developed overseas around 1979. It has been in general use in clinics and hospitals throughout Taiwan for almost a decade, and it is in this period that the figures for the ratio of male to female births have begun to show a marked distortion.
台大醫學院婦產科教授柯滄銘表示，國外在一九七九年前後發展出抽取胎兒細胞組織的絨毛檢查技術，國內普遍應用到一般診所、醫院將近十年，國內男、女嬰比例也開始出現明顯差距。