'Mono Mono' Twins Make Great Strides

A rare set of "mono mono" twins—who shared an amniotic sac and placenta—were born just before Mother's Day; now they may be set to leave the hospital in time for Father's Day. Though they needed breathing assistance after their birth at 33 weeks, Jenna and Jillian Thistlethwaite are both gaining weight and taking full bottles, the AP reports. If the twins' health stays on track, they should get to go home (that's Orrville, Ohio) within the next two weeks.

Meanwhile, their parents, Sarah and Bill, have achieved celebrity status, getting stopped by well-wishers when they're out, they say. That's thanks in large part to a photo showing Jenna and Jillian born holding hands that's made the rounds online. Their father is looking forward to showing them the picture a few years from now. "I already feel like they're going to be best friends," he said. "They'll probably look at it and say, 'That makes sense because that's how we are.'" A week after the Thistlethwaite twins were born, another pair of "mono mono" twins were born at the same Akron hospital; they're doing well, too, a spokeswoman says. A doctor there tells ABC News the chance of one hospital delivering two such sets is "probably [on] the order of one in a million to one in ten million."