自願性指南與強制性法規對試管嬰兒胚胎植入的影響：以台灣為例

Impact of voluntary guidelines versus mandatory regulations on embryo transfer in IVF：evidence from Taiwan

目標：本研究檢視台灣體外受精胚胎移植數限制之雙軌監管模式，比較具有法律強制力的《人工生殖法》與專業自律指引，分析其對臨床實務的影響及母嬰健康後果。方法：利用「人工生殖資料庫」（1998-2017），依據台灣生殖醫學會指引及2007年《人工生殖法》規範，分析胚胎植入數、臨床懷孕率與活產率（每植入週期），以及不良母嬰健康指標之時間趨勢。結果：平均胚胎植入數由4.19降至2.36。然《人工生殖法》採用缺乏「年齡分層」的上限設計，違背最佳「單胚胎植入」實務與「愈年輕，愈少胚胎」的國際共識。此寬鬆的法規設計致使多胚胎植入仍持續存在，尤集中於年輕女性（<35），進而增加母嬰健康風險。結論：缺乏細緻年齡層分的強制性法規，恐引發醫源性負面效果並削弱專業指引影響力。未來應優先推動年輕女性（<35歲）的單胚胎植入；同時，在確立嚴格法定基準以保障群體母嬰安全之際，必須保留具實證基礎的臨床例外彈性，以確保個體化醫療的靈活度。

Objectives: This study examined Taiwan’s dual regulatory approach to embryo transfer limits in in vitro fertilization (IVF), focusing on the effects of legally mandated restrictions and voluntary guidelines. This study addressed two questions: (1) How does this dual system affect IVF practices? and (2) What reproductive, maternal, and neonatal health outcomes are associated with adherence to these regulations? Methods: Data were obtained from Taiwan’s National Registry of Assisted Reproduction and included 178,933 embryo transfer cycles performed between January 1998 and May 2017. Key metrics, including the number of embryos transferred (NET), clinical pregnancy rates, live birth rates, and maternal and neonatal health outcomes, were evaluated across periods defined by the implementation of three NET restriction policies. Results: NET decreased from 4.19 to 2.36 over the study period, indicating a shift toward single-embryo transfer (SET). However, the Assisted Reproduction Act imposed age-insensitive restrictions that conflicted with optimal SET practices and the principle of transferring fewer embryos to younger women, leading to persistently high multiple-embryo transfer (MET) rates, especially among younger women, who experienced increased maternal and neonatal health risks. Conclusions: Mandatory regulations based on uniform transfer limits may inadvertently produce adverse outcomes and weaken the effectiveness of voluntary guidelines. Future policies should prioritize SET to reduce the cascading risks associated with MET, especially among women aged <35 years. The optimal regulatory framework should establish strict statutory standards to protect population-level health and preserve clinical exemptions that enable individualized medical care.