LittleDd, once u go into labour, you can start epidural. I only got mine administered, when... i cannot take the pain anymore, which was like 45 mins before the bb came. But i think due to my higher threshold, i could still hold myself still for them to do it.
Advice is to take earlier. Cos when the contractions come big time, i was squirming in bed and cannot lie still. Epidural needs about 30mins to 45 mins to take effect.
But that said, the nurses and gynae will give u the best advice. Cos i have seen friends who went in and immediately ask for it, and the labour was so long and slow, that they had to get another round of epidural. $$$$$$$
I remember the TMC talk mentioning that there will come a point when they cannot give epidural anymore. Some time when the bb is already on the way out. Or beyond 8cm dilation.
So for me... it was only useful for the birthing process and the stitching up after that.
Maybe because i take mine at a later stage, so i didn't get much side effects after that. No puking, no cold shivers, etc.
My detailed scan is 2 Dec! Week 20! Latest to take is week 22.