going back to work soon, how do I tell my boss that I can't work as late as "before-baby" period? I used to be very dedicated to my work, staying back to work till 11plus at mist days.. now I so tired (my lo doesn't sleep thru the night), and I fall asleep after my lo sleeps at 9-10plus..

Yes, I agree with the rest that having a chat with your boss would be the best. Especially since it sounds like you were required to work late frequently in the past. Having the talk with your boss can help set realistic expectations given the change in circumstances. I’m sure most superiors would understand. Hopefully, arrangements could be made such that you can be given the less time sensitive work so that you will not be feeling stress from both ends (work and home). Take care mummy!