A rare set of "MoMo" (also called 'mono mono') twins were born in Tulsa. That's the short, cute term for "monoamniotic" twins, which means the two babies shared the same placenta and amniotic sac but had separate umbilical cords.
"Rylie, the chunky one, weighed in at 3 pounds; Haylie, 2 pounds, 10 ounces. Big news ... very rare and very dangerous," a KJRH reporter said about the girls.
"I knew right then and there that it was going to be a long road ahead of me," the twins' mother, Destiny Moman, said.
According to KJRH, monoamniotic twins occur in only 1 out of every 35,000 to 60,000 pregnancies, although some stats says it's 1 in 10,000. Whatever the numbers, it's rare. They're usually delivered at 34 weeks or before, and their chances of survival are around 50 to 60 percent.
The twins' mother, Destiny, was due Feb. 2, but she went into labor Jan. 6 and delivered Jan. 7. The major risk for monoamniotic twins is that their two umbilical cords can easily become entangled and cause issues.
Little Rylie and Haylie will remain in the NICU at the St. John Medical Center in Tulsa until late March, which would have been their full-term due date.
And of course the proud parents have been giving updates on Facebook. The twins are both doing well.
This isn't the first time that a set of rare twins have gone viral. A photo of 'mono mono' babies Jenna and Jillian Thistlethwaite holding hands just after birth drew worldwide attention in 2014. Six months later, the twins were thriving. Though the global attention had died down, the siblings were -- and are -- still inseparable.