(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 KPGE reported.

These newborn babies at @CommunityMed are cousins, born one hour apart last night. But guess what? Their moms are TWIN SISTERS!! 👭These twins say they've done everything together... but never thought they'd be pregnant together and have babies together! More in my story,tonight! pic.twitter.com/ODN5DdyKsd — Connie Tran (@MissConnieTran) November 5, 2018

"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 KPGE.

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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