A savior sibling¹ (or saviour² sibling) is a child who is born to provide an organ or cell transplant to a sibling that is affected³ with a fatal disease that can best be treated by hematopoietic stem cell transplantation.

Savior sibling指生下来就是为了给患有致命疾病的兄弟姐妹提供器官或细胞移植的小孩，译为“救命手足”。患病一方一般都需要通过造血干细胞移植才能治愈。

The savior sibling is conceived through In Vitro Fertilization. Fertilized⁴ zygotes are tested for genetic⁵ compatibility, and only zygotes that are compatible with the existing child are implanted. Zygotes are also tested to make sure they are free of the original genetic disease.

救命手足多通过试管婴儿生殖技术获得。受精卵会先经过基因匹配试验，只有完全与患病一方完全匹配的受精卵才会被植入。另外，还要通过试验确保植入的受精卵不携带基因原本的疾病因子。

The term savior sibling is likely to have controversial overtones for some time. Some disagree with the idea on ethical⁶ grounds, arguing that the long-term social and emotional effects on the donor⁷ sibling are unknown.

Savior sibling这个说法一直以来都颇受争议。有人从道德角度对其进行批判，认为捐献器官的孩子长期受到的社会和情感影响是外人无从得知的。