I think a generally safe approximation of with regard to baby's affect on the parents lives:
Pack up your life in box, both breakable and precious (like fine China) along with heavy and indestructible (cast iron pan) as well as the messy (Styrofoam peanuts) and fun (LUBE!).
Turn upside down and shake vigorously. (Never Ever ever never try this with an actual baby!!!)
After the first year, see what's left.
In terms of how this will affect you? It's a matter of how your relationship is with them...China, Cast Iron, Styrofoam or Lube?