Your DD could just be going through a growth spurt/developmental leap, or you could be lucky enough to have a bub that sleeps through!
My DD has had a few nights where she has slept through (8+ hours), but for the most part she does a 5-6 hour block followed by a 3-4 hour block. My DD has always been a quick feeder, 5-10 minutes most feeds (unless she's sleepy). Now that she's a bit older she even goes longer between feeds, so she can go 3.5-4 hours between feeds, and then only feeds 5-10 minutes. I keep thinking she can't be getting enough, but her wet nappies and impressive weight gain tell me she must just be a really efficient feeder. Enjoy it .
It sounds like your little girl is getting what she needs and doing exactly what babies do .
You are doing fine! DD2 was like this until 4m and then she changed but that's the thing - they are always changing their sleep to suit their developmental needs. As long as she is feeding at least 5 times a day and doing lots of wet nappies she sounds fine to be sleeping that long.
Her weight gain seems great - mine didn't hit the 5kg mark until 4 and 5 months old! If she is happy, alert and wet then you are doing the right thing.
Both my little ones have done this, in fact DS who is only 5 weeks has gone quite a long time overnight too 10- 6 (he is already 5kg!), but he doesn't do it every night and his output is great so am just going with it. Have you tried hand expressing? I never liked the pump and if I feel overfull I just hand express a bit, is a bit of a pain waking up even though they don't but it all settles down eventually.
Output overnight is often much less than in the day (just like us), my DS is a much faster feeder than his sister was but 10 mins for Isla's age sounds reasonable to me.
Sounds like you are doing a great job, if she takes to sleeping longer overnight you may find she wants more feeds in the day (or just feeds constantly in the early evening)
Sweetheart you are doing fine, don't have any advice but to say your DD is as bright as a button, inquisitive and is putting on weight, I could tell she had put on weight between the times I'd seen her.
Bookmarks