The scourge: moral implications of natural embryo loss.

It is often claimed that from the moment of conception embryos have the same moral status as adult humans. This claim plays a central role in many arguments against abortion, in vitro fertilization, and stem cell research. In what follows, I show that this claim leads directly to an unexpected and unwelcome conclusion: that natural embryo loss is one of the greatest problems of our time and that we must do almost everything in our power to prevent it. I examine the responses available to those who hold that embryos have full moral status and conclude that they cannot avoid the force of this argument without giving up this key claim.