Thomas Gray lived six days, but his life has lasting impact: When she found out early in her pregnancy that one of her identical twins would die at birth, Sarah Gray began a five-year journey that culminated last week in Philadelphia.
She had to carry the sick baby to term in order to protect his healthy twin. And she also looked into organ and tissue donation.
"Instead of thinking of our son as a victim," she said, "I started thinking of him as a contributor to research, to science."