Two Russian girls, now 12 years old, recently found out they were switched at birth.

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ow do you say "big oops" in Russian? Two families in western Russia have discovered that their daughters were switched at birth — 12 years ago. Here, a brief guide to Russia's "shocking" switched-at-birth scandal:

What happened?
In December 1998, in a maternity hospital in the Ural Mountains town of Kopeisk, two baby girls were given the wrong name tags and sent home with the wrong parents. Twelve years later, one of the mothers figured out what had happened.

How did the mother realize the mistake?
When Yuliya Belyaeva was getting a divorce earlier this year, her husband refused to pay alimony and claimed he hadn't fathered their daughter, Irina. DNA tests showed that neither was Irina's biological parent. It was then that Yuliya thought back to the maternity ward and the other baby girl born on the same day. An investigation confirmed her suspicion that there had been a terrible mistake. "Their daughter, Anya, was blonde and looked just like me and my ex-husband," says Yuliya. "And our daughter was dark-skinned and had dark hair and looked like the other father."

What now?
The families are suing the hospital for $158,300 in damages, and both daughters have chosen to remain with the parents they've known their entire lives. "Irina keeps saying to me, 'Mum, please don't give me away!'" says Yuliya. "I comfort her by saying, 'I would never do anything against your wishes. Nothing has changed. I'm still your mother.'" Yuliya's biological daughter, Anya, also wants to stay put, while visiting Yuliya on occasion. Anya has been raised a Muslim, Irina has not. "They have completely different traditions and customs," says Yuliya. "That makes it even harder."  

Sources: BBC News, Sydney Morning Herald