I've heard that old wives tale many times before. If it were true, then it would be an even worse idea to sleep with pets (or spouse!) in the same room as they use far more oxygen than a plant does. And you don't hear of people droppping dead when walking into a greenhouse at night.
I have a fairly huge pothos in my bedroom, which crisscrosses the headboard multiple times and has now wandered along the walls to the other side of the room. And I'm not dead yet!
I'm probably more at risk of tripping over the plant and breaking bones in the middle of the night than dying of suffocation.