"I've been practicing high-risk obstetrics for about 35 years and I've seen less than 10 cases," said Dr. Justin Lavin from Akron General Medical Center.
He said mono mono twins occur when the same embryo splits more than eight days after fertilization.
Sarah, an eighth grade school teacher, was stunned by the news.
"We were so excited that we were having twins and so that was great, and then you have the flip side of it that I knew I would have to be in the hospital for eight or nine weeks," Sarah said.
The risks, Dr. Lavin explained, include cords becoming entangled or compressed.
The couple has a 15-month-old son, Jaxon. For Sarah, being away from her toddler has been the hardest part.
"We're trying to keep his life as normal as possible so he comes up and visits for a couple of hours," Sarah said.
"It's hard to be here, be we know in the end, we're going to end up with two twin girls and they're going to be healthy and everything is great," Sarah said.
On Sarah's 58th day in the hosptial, Dr. Katherine Wolfe and Dr. Melissa Mancuso from Akron Children's Hospital delivered the twins by Caesarean section at 2:41 p.m. Wolfe and Mancuso had closely monitored the high-risk pregnancy for several weeks.
The couple named their new daughters Jenna and Jillian. They were born at 33 weeks, holding each other's hands.
NewsChannel5 was allowed access to the special delivery and the parents beamed with pride as the sisters, each weighing less than five pounds, entered the world.
Doctors said the babies appeared to be doing well as they were taken from the delivery room to receive their Apgar score, which assesses the health of newborns.
As unusual as it is to have one mono mono pregnancy, doctors were blown away when the learned a second mono mono mom was being admitted to Akron General.
Amanda Arnold, 24, of Akron, is due to deliver twin girls next week and plans to name them Janiya and Amanda.
Arnold, who also has a 5-year-old son, said twins run in her family, but she was still taken back the mono mono pregnancy.
"The first one, she (ultrasound tech) looked and it was just one baby to the side and she was like, 'Wait a minute. Don't count on that one. Let's look all the way around.' The other one, they were sitting side-by-side just looking at each other. I sat up and said, 'That is not two heads.' And, she was like, 'Yeah.'"
"It's pretty surprising to have two at the same time," Dr. Lavin said.