Since Leap Days only occur once every four years, the odds of giving birth to a child on Feb. 29 are relatively small to begin with. So what are the odds of parents having two Leap Day babies?

That’s exactly what happened to one Michigan couple.

Columbus residents Chad and Melissa Croff welcomed their daughter, Evelyn Joy, into the world at 3:06 a.m. Monday, the Henry Ford Health System announced in a news release.

The 6-pound, 9-ounce girl was born four years to the day after her big sister, Eliana Adaya.

Henry Ford officials said both sisters were natural births. Evelyn was born at the system’s Macomb Hospital, while Eliana was born at the system’s hospital in West Bloomfield.

“It’s quite the miracle,” Maureen Heinz, the nurse midwife who delivered Evelyn, said in a statement. “It’s not something they tried or planned to do, and she wasn’t induced. It was all by chance.”

The hospital said Evelyn was due on Feb. 19, but arrived 10 days late.

In a statement, Melissa Croff said she went into labor while attending church on Sunday.

“I didn’t expect the possibility of them being born on the same day, let alone on Leap Day, until I went into labor,” the mother said.