Yes, it's easy. Would both biological parents want their real child back?, yes they would, would a 12 month old infant know whas going on?, no i would not. Switch the babies.
When was the mix up found?, a day, a year, twenty- five years later? If it is the latter, lets hear your words to that adult child when your wife and five children are listening.
Then you tell them what happened, obviously separate lives have been lived that cannot be undone. You need a full scenario to even debate this. Ie: when was the mix up detected.
It's the best. Aside from Hospitals, there are lots of walk in clinics, and everybody gets looked after. But we only have a population of 34 Mil, 11 times less than the US.
RE: Switched at birth
Either way, you switch them right?