
A bitch can need a C section for many reasons, but it's definitely an issue of genetics in many cases.
Two of my bitches have had C sections, both for their third and final litter. The first was a non progressing labour, (previous litter more than three years earlier) and the second her Great Granddaughter we believe was a malpresentation as first puppy born easily and then two hours later bitch distressed and panicking.
Had either had a C section for malpresentation in a first or second litter, then I'd have another litter with at least one season, but preferably two seasons left clear before mating on the next, but that's my norm anyway.
I would not do a planned section.