I kept loads of stuff from my eldest, obviously for the reason that if I had another boy ,then they would get used again, but I had two girls and didn't get a boy till my eldest was nearly 7, so when I pulled all the boy stuff out, most of it had perished because it had been kept so long (cuffs and collars and elastic waistbands etc). All the quality stuff I brought was OK, but everything else wasn't useable so I had to toss it. In hindsight I should have gotten rid of it so someone else could have had use of it, but you live and learn I suppose. Now I don't keep anything - if it isn't going to be worn in the next season or so, I give it to charity. Naturally there is stuff that I've kept that has sentimental value. Its up to you though, but you also have to consider that your next baby might be the opposite gender and out of season.