My LO is 7 weeks, 11 lbs and still seems like she has a little bit of time in newborns. I hve some 03 but they aren't the best fit yet...
How long did your LO remain in newborn? What weight/height?

Little Riley-our first little girl coming March 1st, 2013 (or sometime around there;)
Re: How long in newborn clothes?
It depends on how the NB sizes are made, some stuff he outgrew in 3 weeks, a few pairs of pj's he was in until 6 weeks. We have been putting 0-3 on him since the beginning because we didnt have much newborn, and just tucked and rolled as needed. He's almost 10 wks now and is 11 1/2 lbs
DD3 has been slow to gain weight. She's 8.2 lbs and around 23" at 4 weeks. NB sizes still fit, but she mostly wears 03m sleepers bc that's what we have.
Charlotte Ella 07.16.10
Emmeline Grace 03.27.13
I would say when she was about 9lbs max. She was 8lbs even when born and wore them for about 2-3 weeks.
We just switched her to 3-6months clothes yesterday and she is just over 10lbs6oz. She is about 23" tall and needed the length of 3-6month clothes.
I'm pretty surprised an 11pounder could still fit NB!
I think a big part of it is parent preference as well. What I see as small may seem big to another mom. It's the same with diapers some parents like the loose some like them really snug they all think they are the right size though. The more use your get out of them the better for your pocket book!
DS never wore NB. He was 8#7oz, 21.5 inches long, he was too long for them. Now at 5 weeks, he's getting too long for 0-3 months :-( He was 23inches at his 1 month appt
DD1: Summer didn't hit ten pounds until nearly 4 months. We switched her from NB clothing at 2 months. She was getting to long.
DD2: Leah, she was really short, actually she still is, but a bit heavier. She grew out at 6 weeks.
DD3: Eryn, was along the same size and time line as Summer. She is now 8 months and just moving into 6-9 month clothing.
DN1: We have custody of my niece and nephew. Niece since the day she came home from the hospital. She was in NB until 4 weeks, moved to 0-3, but she needs 3-6 month sleepers. She is quite long and only four pounds less than Eryn. She is a valentines day baby.
1 month with DD1 (7lbs 5oz 20.5in at birth), 3 weeks with this LO (7lbs 13oz, 21in)
For both it was a length thing. They could do 2 piece outfits a bit longer but the footy pj's scrunched their poor little feet!
DD was 8lbs 7oz at birth and was out of nb clothes at 4 weeks. At 7 weeks she is now about 12lbs! She is a pretty chunky baby
A lot depends on the clothing manufacturer. DS is already too big for his Gerber's 0-3 onesies, yet he can still wear a few Carter's NB items. DS was born at 8lbs 4oz, 19.5 inches, and is up to around 10-11lbs, not 100% on his actual length right now. We started noticing about 1-1/2 weeks ago that his Gerber's onesies were fitting a little snug.
This. DD is 12 weeks, a little over 12 lbs and over 24 inches, and she STILL wears newborn clothes. Of course, no footie pj's, but onesies and snap up pj's still fit. She's long and lanky but very stout. 0-3 months fit well, but 3-6 months are way too big.