When I had DD1 I passed out 3 times. Reasons being...
1, I was exhausted. I'd had 4 hours sleep in the 3 days leading up to it. Just half hour the night I went into labour.
2, I had pethidine, as well as gas & wasn't breathing properly on the gas, so I was hyperventilating as well.
The contractions would wake me up & I was wondering what on earth was going on! I'd completely forgotten I was in labour.
I was so high I was seeing purple sparkly flowers!!! Til the contractions brought me crashing back down to earth, lol!!!