Different countries have differnt ways I guess. Here only under certain cirumstances like when a baby has reflux and can choke on her own vomit, is sleeping on the stomach recommended. When my son was born 10 years ago, they allowed sideways but still recommended sleeping on teh back. When my daughter was born 5 years ago, the sidesleeping was frowned upon completely. The reason is newborns can’t turn by themselves and therefore can suffocate. For gas etc what Devilsih angel says is recommended.