Micro preemies - although they all look pretty micro - are the very smallest. We define this size as up to 3 lbs although there is a huge difference between a 1 pound baby and a 3 pound baby. And there are differences in 3 pound babies - some are just born, perhaps in very fragile condition still and with many wires and tubes hooked up to them. Some have been in the NICU for weeks already and have worked up to that weight and are now mostly growing and getting used to breathing and eating on their own and can wear more clothes in preparation for going home and keeping themselves warm.
The clothing needs of the tiniest babies are probably more for the parent's sake although some feel babies are more comfortable not being naked or uncovered. But regardless, they have to be soft and easy on their skin as well as easy to use and compatible with whatever wire and tubes there are.
We try to have the largest selection possible of clothes that work in these conditions and that fit the needs of this range of babies.
Many years ago I received a cute story from a mom of very small twin girls. They were dressed in tiny dresses I had made and when the nurse went to undress one girl the baby got a grip on the dress and held on so tight they didn't pull it away from her until she finally let go quite some time later. Mom said it was like the baby wanted to keep the little dress on!
Here are some examples of very tiny, very easy to use items.
And some for slightly larger babies able to wear more clothing.