My 3 months old baby always sleeps by his tummy? Is it ok to allow him to sleep at night like that ?

According to experts it is not advisable to let babies sleep on their tummies. The safest sleep position for your baby is to sleep on his back. The back sleep position carries the lowest risk of Sudden Infant Death Syndrome or SIDS. Research also shows that babies who sleep on their backs are less likely to get fevers, stuffy noses, and ear infections.