My DD is 5 weeks old. She's recently begun to sleep for longer stretches at night. Last night, she slept for 7.5 hours. My understanding was that as long as weight gain is normal and baby is healthy, at this point it's fine to let her sleep until she wakes up. (and she is -- was weighed yesterday at the pedi and her weight was exactly where it should be on the growth curve) However, DH is very concerned that 7.5 hours is too long to let a baby that young sleep w/o nursing -- he's worried about dehydration. He remembers hearing that she shouldn't go longer than 4 hours at this point, but we can't find where he got that.
What do you wise mamas out there say? I've tried to look it up in some of the baby books I have, and a few online sites, but everything seems focused on babies who aren't sleeping for long periods of time (i.e. - the section on "sleeping through the night" says "don't be discouraged when your baby doesn't sleep for very long", it doesn't say anything about how long is "safe"). I'd love to encourage her to sleep through the night if she's ready and able to do it, but only if it's okay to do so at this point.
As a side note -- I'm EBF at this point. If she starts sleeping that long consistently, I'm figuring I should probably pump somewhere during that time, right? I was very uncomfortable by the end of the 7.5 hours last night! I'm also going to be going back to work full time in a month, so I figure it'd be a good time to build my stash.