It's pretty remarkable how insignificant the male contribution to birth actually is.  Jim Gaffigan covered this pretty well in his standup special.  But really, aside from the initial part (sex), here's a list of things the male participant doesn't do: 
  1. Grow a fetus inside their body.
  2. Grow an additional organ (placenta) inside their body.
  3. Figure out how to use an organ they've never used before (uterus) to safely eject the fetus from their body.
  4. Feed a human with their body.
I knew I would be mostly on the sidelines for this, but honestly it's kind of embarrassing. #lifestyle