My daughter was born extremely prematurely and needed oxygen for a while. Sleep, especially REM sleep (which is actually one of the “shallower” stages of sleep) is where blood oxygen is generally lowest. Therefore, we had to do a sleep study (just monitoring blood oxygen and heart rate) to make sure her lungs were developed enough to go off of oxygen day and night.
I’m assuming your lungs are pretty well-developed, but if you have something going on that may impede your blood oxygen levels, there is that at least.