Karina I was in a similar situation with my last job. I did not want to work full-time after bubs was born, but if I wanted my job back definitely I had too. The child care situation in my area is dire, I managed to get 1 day per week when Maggie turned one, and I had her down since I was 5 months pregnant. As I could not guarantee to go back I decided to resign, I just did not want a job hanging over my head. Also I wanted to take advantage of the time off to start my own business. I just did not feel right doing that whilst on official maternity leave. I actually liked my workplace and boss, it was just this one area they were not flexible in.

At the end of the day do what you feel comfortable with.