Jonah was delivered C-section because Jo's doctor was
suspicious of some redness down below that he thought might
be a hint of vaginal herpes (Jo Beth had never had symptoms,
so SHE wasn't worried about it.)  It is dangerous for newborns
to come into contact with herpes.

Compared to pneumonia and a broken rib, being sliced open
for the C-section was nothing.  Compared to weeks of pain
after Justin's vaginal birth, and two surgeries Jo needed
afterward to pin all her parts back in place, the C-section
recovery was also nothing.
A C-rrific Way to Give Birth
Jo Beth tells her friends:

"Ladies, a C-section is the ONLY
way to go!  When it's your turn:

Have them put a zipper in."
Take me back.
While Jo Beth was lazing around on the sofa doing nothing, so
were her muscles.  Maybe that is why one day, when little
Justin  jumped up on her joyfully to give her a big hug, Jo
Beth felt one of her ribs crack. Lazing around in a prone
position is probably also why Jo Beth got pneumonia.
By the time Jonah was finally
ready to ease on out,

Jo Beth was just about ready to
yank him out.