Sarah Thistlethwaite, an Ohio mother, gave birth to twins with a rare condition last year.
The twins, named Jenna and Jillian, shared an amniotic sac and placenta–a condition that’s known as monoamnioitic, or “mono mono.” They came out holding hands, and photos of the girls went viral when they were born.
Doctors have said it’s the rarest form of pregnancy among twin births.
There were fears of their survival when they were born, but few weeks later, they were healthy and strong. But they felt most comfortable holding hands. However, at the time, parents Sarah and Bill said they had trouble telling the two apart.
“Actually Jillian, the way you could tell her from her sister, she is a little bit smaller, about a pound difference between them and Jillian has a birthmark above her left eye and eyelid,” Bill Thistlethwaite told WJW-TV in Ohio.
“I had a lot of anxiety at the beginning, especially, when I found out they were mono mono twins – just whether or not they were going to survive,” added Sarah. Sarah was in the hospital for 56 days over concerns about cord entanglement or compression.