[clover]

My current newborn is almost 7wks and 13lbs... Both work on him at this point, but the smalls are much trimmer and just seem to fit better, so I'm not using the OS yet. He was 10.5lbs at birth and the smalls were awesome on him right from the start. I think especially if you will probably have an average size newborn (7-8lbs) the smalls are worth it. Even at 13lbs he still has a lot of room to grow in the smalls.