(CNN) — Twin sisters in California passed on their tradition of sharing a birthday, giving birth to baby daughters within an hour of each other.

Fresno sisters Bao Nhia Julia Yang and Bao Kou Julie Yang, 23, unexpectedly went into labor at the same time, although their due dates were two days apart, CNN affiliate KGPE reported.

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“I started having like, I started spotting, so I think I knew that I was going to be in labor. And then I told her, and she was like, ‘I’m having pain here and there, too. I might be in there with you, too,'” Bao Kou told KGPE.

Sure enough, both had baby girls Sunday night at Community Regional Medical Center in Fresno.

“It’s like a miracle,” Bao Kou said.

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Laura Schleicher, a nurse who helped deliver the babies, told KGPE that in 18 years at the medical center she’d never seen twins give birth on the same day.

“They just had great timing, very unique timing,” Schleicher said.

Bao Nhia told KGPE that her daughter Candra Thao weighed 7 pounds, 3 ounces. Bao Kou said her daughter Nadalie Xiong was “7 pounds, exactly. Almost the same!”

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