When 29 year old Dr. Clinton Battle was called to a home in Indianola, Mississippi, in 1955, he had no idea that the twins he would be delivering were conjoined.

“[Our mother] was in labor and they couldn’t figure out what was going on because my twin here … I was coming out and then going back in,” Lillian and Linda Matthews explained over each other recently when they spoke with Sam Brock on the Today show.

Dr. Battle finally recognized what was happening as he delivered the twins from the mother who had not received any anesthesia. That wasn’t the only complication either–one of the girls had a heartbeat, but wasn’t breathing.

They were rushed to South Sunflower County Hospital where they weighed in at 11 pounds and 6.5 ounces. Doctors discovered Lillian and Linda shared a liver and were connected to each other from the sternum to the navel. Then, at only 5-weeks old, doctors were able to separate them in what was believed to be the only the second such surgery ever performed.

The little girls thrived as part of a large family with nine other brothers and sisters. They grew up to be teachers and went on to have children of their own despite being told by their doctors that it wasn’t possible for them to have children. Today, they have seven, plus 16 grands that prove the doctors were wrong. These ladies, retired teachers now, want their remarkable story to bring hope to other parents of conjoined twins.

Conjoined twins are considerably high-risk as they are often born prematurely. They also run the risk of being stillborn, dying shortly after their births, and health problems throughout their lives. There are a couple of theories about how twins can be conjoined. One theory is that a fertilized egg starts to split into two, but the process is stopped before the split is completed. The second theory is that two embryos join together inside the womb.

But the special surprise birth of Lillian and Linda and their successful separation have since led to more lifesaving surgery for conjoined twins. And they are proof conjoined twins can survive and lead healthy, full lives.