After my 3 month maternity leave, I went back to work for 3 months... It took us a little extra time to sort out the finances. I was miserable. I was a retail sales manager, so if you only work 40 hours a week you are a slacker. A typical week was between 55 -60 hours, but busy times I could easily be at the store 70+. Not the best situation if you have small children.
My husband & I refinanced everything we could to get lowered interest rates, cut down on unecessary expenses to make it work. I made about $15 thousand a year more than DH. It was very hard to cut our income in more than half, but we didn't have the expenses of working at a department store (lunches, coffee, clothing, SHOES!).
Write down ALL of your daily expenses (gas, food, clothing, dry cleaning etc.) it is surprising how much you spend just going to work everyday. Then start calling daycares and find out how much having an infant in day care will cost. All of a sudden it seems very reasonable to have someone staying at home. We have had some tight months, but we are still swinging it.
Also, depending on what you do, there may be a possibility of freelance or part-time or part-time at home. I worked for a year a merchandiser. I was able to work evenings after DH got home.
So after all of that
... what I'm saying is that it is do-able. Be creative!