Suffocation from co-sleeping is NOT SIDS.

https://www.webmd.com/baby/news/20180212/baby-suffocation-de....

Perhaps the parent comment is referring to a theory that parents reporting the situation around baby deaths as unexplained in order to deny blame or guilt for having placed the baby in the situation. There can't be much worse so it wouldn't surprise me if in the traumatic following days the recall isn't factual and unbiased.

Since the nineties they started advise parents that all infants should sleep on the back, which reduced SIDS a lot [0]. But it means that it is is very hard to draw any conclusions at all about other factors.

[0] https://safetosleep.nichd.nih.gov/research/science/backsleep...

Not in all countries. In my country we lay them on their side supported by a rolled towel. We make sure they equally lay on both sides. Sleeping on the back will give them a flat head.

> Sleeping on the back will give them a flat head.

I'm fairly certain this isn't true. I would expect there to be a lot more flat-headed babies and people around. I don't think I've ever seen one. Not telling you what to do, just pointing out I don't think that part is factual.

It’s certainly true. Our oldest kid had a quite flat head when he was an infant, so we had to get him a special pillow and was advised to try to let him sleep on the side. But it’s nothing that you think about except when you put your hand on the back of his head, and most of it will allegedly disappear when the scull grows.

And if you think my anecdote is enough, Google will provide you with plenty, e.g., [0].

[0] https://www.nhs.uk/conditions/plagiocephaly-brachycephaly/

If you look around you will start noticing it. A babies skull isn't even fused and has soft spots (fontanelle) so it makes perfect sense that it can be shaped and molded as it develops and grows.

Smothering is a much bigger problem if the parents in question drink alcohol before cosleeping.

This! My wife did a lot of reading in this when our kids were babies and her takeaway was that alcohol/drugs are responsible for most smothering events and that SIDS is actually reduced by co-sleeping - something about the mother’s breathing training the baby to breathe rhythmically. I believe she found a study on this point - I’ll try to dig it up and if I find it I’ll edit this comment with a source.

Please do, I’d enjoy reading that.

Ball & Russell (2014), SIDS and infant sleep ecology. Evolution, Medicine and Public Health 146. [0]

Not a study, but I believe this was the article that got her started down the rabbit hole of looking more deeply into this research. We were both surprised to learn that SIDS is significantly more prevalent in western societies that do not have cultures of co-sleeping, and that SIDS primarily occurs when babies are alone. I am struggling to find the article that discusses the breathing component directly, but this touches on it with reference to poor neurological development of human babies and associated weak physiological regulation.

This was the a ha! moment:

“SIDS-deaths are a phenomenon of infant sleep in Western post-industrialized cultures, normally occurring while infants are alone. … Immigrant groups who maintain their ‘traditional’ sleep ecology in ‘Western’ environments typically exhibit substantially lower SIDS rates than the host community.”

This UNICEF page compiled good research on co-sleeping too. [1]

[0] https://academic.oup.com/emph/article/2014/1/146/1846850

[1] https://www.unicef.org.uk/babyfriendly/news-and-research/bab...