@ancienthouse @PuddingBear @MamaMenna yessss let's spread the word about normal and biological infant sleep! It's so important - agree with everything you've said.
@Chocolat I think the thing about being in same room as baby is also to do with the fact that the air actually changes due to our exhales etc, which can help to prevent SIDS so not necessarily about baby being able to hear our breathing - but this would help too I'm sure. The book Sweet Sleep by La Leche League has an excellent chapter on SIDS, I'd recommend it anyway as a fab resource to navigate baby sleep if breastfeeding. Another great book for infant sleep is The Gentle Sleep Book by Sarah Ockwell Smith.
While scary, don't worry too much as SIDS is incredibly rare and even more so if you breastfeed - and having baby sleep in the same room as you for all sleep/naps for the first 6 mo at least will help to protect further.
Safe cosleeping/bedsharing, following the safe sleep seven guidance www.llli.org/the-safe-sleep-seven/, also helps to reduce risk of SIDS as being close to mum will help to regulate temperature and breathing, plus encourages easy night feeding. Tiny babies just need a bit of help to human, I like to think haha. They're designed to be close to us, and 100% dependent on us.
Other risks like suffocation or strangulation while sleeping are actually different to SIDS, and of course can be mitigated against by having safe sleep surfaces for baby and keeping baby close. There's loads of information and it's hard to know where to turn/what to trust, but you have plenty of time. And your instincts when baby is here will help!