Andrew Donovan Lee and Garrett Lee Donovan Stancombe share both a heart and a liver, CNN said, which makes the chances that they could be successfully separated very low. There are no known cases where twins have survived such a surgery, CNN said.
"It would hurt us to lose one and have the other," the twins' mother, Michelle Van Horne, told WTAE. "They were born together; they can stay together."
The boys are out of the hospital and home with their parents, Van Horne and Kody Stancombe, both 25, People reported.
About 200 sets of conjoined twins are born each year, CNN said, though half die before their first birthday. The overall survival rate of conjoined twins is between 5% and 25%, WTAE said.
For now, the boys are doing as well as can be expected, People says, though they are on different sleep schedules -- a common problem with twins.