胚胎著床前染色體篩檢(PGT-A)在選擇性單一胚胎植入(e-SET)所扮演的角色

The Role of Preimplantation Genetic Testing for Aneuploidy (PGT-A) in the Elective Single Embryo Transfer (e-SET)

選擇性植入單一品質好的胚胎（e-SET），是現階段醫學界推廣的植入方式，e-SET可以幫助女性避免「懷孕多胞胎」承擔的身心健康及胎兒自身風險。至於如何選擇單一品質好的胚胎，胚胎著床前染色體篩檢(PGT-A)，可以成為我們現階段篩選胚胎品質的利器：PGT-A的最大優勢在於，植入前能夠識別出較可能健康懷孕的「整倍體胚胎」，對於減少流產率有一定的幫助。然目前技術上PGT-A也有所限制，當面臨PGT-A篩檢結果皆沒有「整倍體胚胎」時，將需要抉擇是否植入「鑲嵌型胚胎」，或考慮擱置「非整倍體胚胎」，再重啟新的週期，卻可能導致治療時間的延長；再者，PGT-A的成本效益難以量化，將是後續臨床與研究探討的重要課題。整體來說，PGT-A能協助臨床端，在抉擇植入何謂品質好的胚胎時，多一份參考依據，在提升e-SET的利用率中，扮演了舉足輕重角色，然PGT-A技術本身所付出的成本，是否符合經濟效益，還需要更多的研究來探討。

Elective Single Embryo Transfer (e-SET) is the implantation method currently promoted by the medical community, as it can help women avoid the health risks associated with multiple pregnancies and the risks to the fetus. Preimplantation Genetic Testing for Aneuploidy (PGT-A) can be a useful tool for selecting high-quality embryos at the current stage of embryo screening. PGT-A can be used to detect extra or missing chromosomes, known as aneuploidy. Most cases of aneuploidy lead to failed embryo implantation or miscarriage. Therefore, the biggest advantage of PGT-A is that it can identify embryos with a higher likelihood of successful, healthy pregnancies before implantation, which can help reduce miscarriage rates and increase pregnancy rates per cycle. However, PGT-A currently has some technical limitations and challenges. When PGT-A results do not show any embryos with whole chromosomes, there is a decision to be made whether to implant mosaic embryos. Also, in order to implant perfect euploid embryos, it may sometimes cause treatment time to be extended. Additionally, the cost-effectiveness of PGT-A is difficult to quantify, as many studies have not considered all the subsequent costs of obstetrics, neonates, and disease/anueploidy. Overall, PGT-A can assist clinicians in choosing high-quality embryos for implantation, which plays a crucial role in improving the utilization rate of e-SET. However, more research is needed to determine whether the monetary and time costs of PGT-A technology are in line with economic benefits.