Re: Does your baby sleep through the night?
The old rice cereal in the bottle is a myth and doesn't work. At least that is what I've heard and my dr. said.
I remember going back to work at 12 weeks too and being exhausted. I was still getting up a lot. I don't think you can expect a full night sleep at that age, but maybe you could get it down to one feeding during the night. You also will want to check with your dr. on how long your little one can go without eating. Assuming he's growing well, they may say it's ok to go the night, but you should ask anyway first.
I don't know you're schedule, but perhaps you could try to get your baby to go back to sleep (it will be hard) without eating when he first wakes and then feed him on the second time he gets up. Eventually he'll sleep through the first waking.
Honestly, at 3-4 months, I was just happy to get my baby to sleep in her crib for more than 4 hours at a time.
I just accepted the fact that I'd be exhausted for a couple of months.