I found this article ( Med Hypotheses. 1995 Apr;44(4):243-50) presenting a medical hypothesis explaining sudden infant death syndrome.
Since a fetus doesn’t breathe, it might remember and mimic that and stop breathing. 
It’s still only a hypothesis, and an 8 year old such, but what do you think? “Dream images are supported by the corresponding body actions, using those muscles which remain active” Is there a potential risk of hurting yourself while dreaming or lucid dreaming?
I read that it’s because babies don’t have the reflex to gasp for air. Wich can sometimes be necessary.
Also I think babies do breathe in the womb. At least a little. Because the fluids in there are breathable. If they don’t breathe it, it doesn’t make evolutionary sense.
They get oxygen only through the navel string i think?
Well, I haven’t researched the subject. I just don’t see the point in having a breathable liquid in the womb if it’s not being used. It’s not for naught. Perhaps it’s just so that the fetus will not drown when the liquid get’s into the lungs.
I only read about it in “illustrerad vetenskap”. Here are links on both things I mentioned.
illvet.se/Crosslink.jsp?d=18 … &id=9905_2
illvet.se/polopoly.jsp?d=147&a=1427
Sorry to anyone interested who does not read Swedish. Aqueous, I’m just gonna go ahead and assume that you know Swedish based on your location, Don’t feel like deleting stuff now that I went through the trouble of looking it up.
Wow interesting! The last article especially. (for you who don’t know swedish: It tells about a liquid that researchers have developed for deep divers and also for use at operations and such, they actually do pour liquid into the test persons’ lungs) Yes i understand you then krakatoa. Maybe they do breathe.
According to Wikipedia: “Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen rich liquid (usually a perfluorocarbon), rather than breathing air. It is used for medical treatment and could some day find use in deep diving and space travel. Liquid breathing is sometimes called fluid breathing, but this can be confusing because both liquids and gases can be called fluids.”
I remember they used this concept in the movie The Abyss.
Anyway, to get on topic, yes, a baby does breathe in the womb. He/she grows inside the amniotic sac, and it’s in this clear liquid that the baby learns to move limbs, open eyes, and breathe. The amniotic fluid helps regulate temperature, keep the baby safe from sudden impact, and also helps him/her develop lungs.
It was an interesting theory, but I don’t think dreaming has much affect on SIDS. 