When I was a baby, my mother was recommended to put me to sleep on my stomach, but of course, there was still no evidence that it was a risk of sudden death. Incidentally, 30 years ago the incidence of the syndrome was much lower.
Since it has begun to recommend putting babies to sleep on their backs (in the early '90s) it has significantly reduced (by 50%) the number of cases of sudden infant death (SIDS). Sleeping posture is one of the factors related to the syndrome but not the only one. Maternal smoking, for example, is proving to have a strong influence, perhaps greater than posture.
There is scientific evidence that this position reduces the risk of the baby suffering from sleep apnea episodes, ie brief interruptions of breathing during sleep, since it favors the passage of air.
But sleeping on your back is also proving to have a negative consequence. It predisposes the baby to suffer positional plagiocephaly, deformity in the baby's head characterized by flattening of the back and cranial asymmetry. Cases have increased by 14%, which is worrying pediatric neurosurgery services crammed with such consultations.
Although the “back” posture is still the position recommended by pediatricians, it is advised to alternate it by placing the baby lying on both sides to prevent the skull from deforming. As you know, the skull of the newborn is still easily moldable.
The motto is that "Plagiocephaly can be treated while sudden death cannot". Strongly agree, but plagiocephaly can lead to disorders and pose a neurological risk. To treat it, the baby is put on a shaping helmet, which in addition to being uncomfortable is expensive and is not covered by Social Security.
Plagiocephaly prevention is very simple. The key is in distribute the time the baby sleeps in all three positions. A while facing up, another on the right side and another on the left side. You should not always use the same way to put the baby to bed, both during naps and at night. You can take advantage of nighttime awakenings to change your position.
Another important and highly recommended factor is that when the baby is awake and wanting to play it is placed on his stomach, resting on his triplet (for example, on a blanket of games) to strengthen the back muscles and develop his motor skills .
