I'd like to hear your definition of sentience. It sounds like it's an unusual one.

> Sentience is the ability to experience feelings and sensations.[3] It may not necessarily imply higher cognitive functions such as awareness, reasoning, or complex thought processes. Some writers define sentience exclusively as the capacity for valenced (positive or negative) mental experiences, such as pain or pleasure.[4]

> Sentience is an important concept in ethics, as the ability to experience happiness or suffering often forms a basis for determining which entities deserve moral consideration, particularly in utilitarianism.[5]

For reference, a lump of cells part of fetus isn't sentient in any sense of that word you could imagine. A braindead woman being kept alive as an incubator for a fetus isn't sentient either. A mentally/developmentally challenged person is sentient.