What would you do? Baby switched before birth

Watching this movie called “baby switched before birth” where 2 couples couldn’t conceive so they got pregnant through fertility. One mother was pregnant with twins and the other lost her baby. Well one of the twins belonged to the couple who lost their baby at 16 weeks pregnant… (the couples was friends) .. so they went to court cause the parent didn’t wanna give up the child to the parents who it actually belonged too. Would you have kept the child or gave it to their biological parents? Baby was 5 months old so it didn’t know what was going on