First things first…. Embryonic stem cells that are used for medical treatments are NOT part of a developing fetus or baby.
Rather these cells are derived from other embryonic tissues such as placenta, umbilical cord, and amniotic fluid. These tissues are routinely collected during the birth of a baby and destroyed (incinerated) immediately following the birth.
From a clinical perspective, fetal stem cells are NOT suitable for any therapeutic use, because they are very unstable and not safe for transplanting into patients.