I have had 2 c-sections (under a general), 1 oral surgery (I was put out) and surgery on my ankle - I shattered the bone (1 plate, 3 screws, 3 pins and wire to help tie it all together).
I
never had a problem with my MS in any of those cases nor did I use anything to prevent an exacerbation.
Wishing you all the best with your surgery