Nope! Some infants respond to a drop in oxygen by stopping breathing all together, instead of breathing faster or trying to get more oxygen. It is thought this

Nope! Some infants respond to a drop in oxygen by stopping breathing all together, instead of breathing faster or trying to get more oxygen. It is thought this is leftover from time in the womb: https://www.frontiersin.org/articles/10.3389/fneur.2015.00220/full https://www.frontiersin.org/articles/10.3389/fneur.2015.0022... Anything that reduces how much oxygen the infant gets can potentially trigger this. So while it might be "there was a pillow the baby managed to roll into", it could also be a mild allergic reaction, acid reflux, a respiratory virus or insufficient air circulation. None of those things would be enough to be a "cause of death", because they were just the trigger for the infant's brain deciding to stop breathing.