Being a dad is not just about biology.
Juan Calvo and his husband, Darrow Brown, know that fatherhood isn't limited to a science. In 2007, after Calvo volunteered to care for drug-addicted infants in Baltimore, he knew he wanted to do more.
So, Calvo and Brown became foster dads. The two still remember the moment they met their first foster child.
"The worker came in, she chatted a bit, then left some formula and said, 'Here, here you go. Sign this paper,' " Calvo says. "And this little baby, he was so beautiful."