My son is now 20 months so it's been a while but I found it exceptionally hard to lose the baby weight. It was awful! I was a maintainer for 7 years and then gained 40lbs (123->163) and holy ****, getting down to 130 took me a year.
There are so many factors, I blame severe sleep deprivation, my son still wakes up at night
Not to mention trying to eat with a colicky baby is HARD!!! And of course, not being able to just get up and work out when you want.