Yesterday's NYT Magazine ran a long article about whether fetuses feel pain. The author, Annie Murphy Paul, is working on a book about how our early experiences shape development, and she asks some interesting questions about what effects pain and stress might have on fetuses. The pain question is an interesting one, and experts disagree about whether, to what degree, and at what point in time fetuses can experience pain.
If fetuses can experience pain, it seems not only reasonable but morally necessary that they receive sufficient anesthesia when they undergo painful procedures (such as blood transfusions or surgical interventions--which, believe it or not, can actually be done in utero in certain specialized centers in the U.S.). Such a claim doesn't rest on assertions of personhood, only of sentience. I would never let a veterinarian do surgery on my dog without anesthesia, but that doesn't make him a person.
As Paul notes, some anti-abortion activists have seized on research that shows fetuses displaying a physiological response to painful stimuli. They want to use this information as an emotional weapon, making sure that women know that if they have an abortion, the fetus will feel pain. Therefore, the argument goes, they should not abort. But while such a statement might make a woman feel worse, I have a hard time imagining that it would really change the mind of a person who'd made a firm decision to abort. It might cause her to ask that anesthesia be provided, though, which seems like a good thing.
Setting aside the abortion debate, pain is awfully tricky. We tend to understand pain as a subjective phenomenon: two people exposed to the same painful stimulus might well have different responses. So what does it mean to talk about pain for the fetus, who can't rate pain on a scale from 1 to 10, or even point at a frowny face? What do measures of cortisol or other stress hormones , or changes in blood flow, tell us about what the fetus is experiencing?
If we say that increases in certain metrics or decreases in others correlate with pain, what would it mean if we saw similar indications in a person in a persistent vegetative state? Paul comments that it might cause one to reconsider active euthanasia in such a situation, as a means of sparing suffering. But the connection between pain and suffering, between objective physiological measures and life as experienced, forces us to think about consciousness, about personhood, about respect for living beings (human and not), and about mercy. I can't do the article justice here, but it's definitely worth a read.