Can you please tell me what the church's position is on stem cell research and use in medicine. Obviously we would not want human life to be sacrificed to obtain these cells. However if, for example, such cells were harvested from an umbilical cord would that be acceptable?
Yes. As long as the stem cells that are used are not obtained by destroying human life then they are acceptable to be used.
You can read more from the USCCB:
Catholic Support for Ethically Acceptable Stem Cell Research