Cord Blood

This will be more applied ethics oriented. Umbilical cord blood is pretty interesting stuff; it's full of hematopoietic stem cells and can be banked as a future source of stem cells for transplantation. Cord blood has been used to treat a variety of hematologic and immune diseases like leukemia and Fanconi's anemia.

Now what's interesting is that you can do autologous transplant with cord blood. If your cord blood is collected and banked as a newborn, and you acquire a disease later on which can be cured with a cord blood transplant, you can use your own blood to save yourself. (Nevertheless, a 2005 article notes the probability of needing this is less than 1 in 20,000).

But take a hypothetical situation. You and your spouse have your first child, and unfortunately, he has leukemia. One treatment is a cord blood transplant, but there are no matches to be found. What are the ethical implications of having a second child solely or partly in order to collect cord blood with a 25% chance of being a perfect match and 50% chance of being a partial match? Indeed, this may cure your first child and poses little risk to the second child (cord blood collection poses no danger to mother or baby; however, there's the interesting question of what if the second child could use an autologous transplant later?) There are pure medical ethics issues such as donor consent; you're asking for a tissue donation from a person who doesn't exist. And there are religious and moral issues about bringing a new person into this world solely or partially to help a sibling.