As a child I believed that a woman birthed her babies through her mouth. I was very concerned as to how a mother could breathe as she was pushing a baby out of her mouth. Thankfully, my mother cleared this up for me (after chuckling a while over my misconception).
A childhood belief about giving birth

others believed things like this
- I used to believe that babies came out of their mother's mouth like a small bubble.— Evelyn
- I used to believe that babies were born through the mom's mouth.
Don't know how I came up with that. — Makenna - When I was little I believed that the mother vomited the baby. Anon
- I used to belive that if i put my foot in my mouth, I would get foot-and-mouth illness— Emily Sathrota
- When I was very little I used to believe that when babies were born they came out of the mother's stomach.— Aerith
- I used to believe that babies came out through the mother's belly and they sewed up the stomach afterwards.— Lucy