I agree that defining an exact moment is difficult and/or somewhat arbitrary, but it seems to me that physical birth doesn't make sense as a cutoff since the ba

I agree that defining an exact moment is difficult and/or somewhat arbitrary, but it seems to me that physical birth doesn't make sense as a cutoff since the baby is usually viable before that point. In my opinion a better milestone is higher brain function which occurs at about 19 to 20 weeks.