Matilda never slept on her back. Even in hospital they had her on her side when she was first born due to heaps of mucos. With her reflux she wouldn't sleep if placed on her back, so she would sleep either on her side but mostly tummy. Before she moved much we would put her on her side with a towel rolled up tight behind her so she had support, once she was more mobile we would just try to get her to sleep on her side.

BTW we were co sleeping at first & in the hospital & she slept on her side & we would swap & go to the other side.