Amongst all the diapers available in the market, size one diapers work just perfectly for newborns as they are designed to fit the babies. However, if your baby is less than 8 -14lbs, they might not fit as newborn size 1 diapers fit accordingly to babies weighing 8 - 14 lbs.The only downside of it all is that these best diapers of size 1 do not come with an umbilical cut-out. But, parents could for sure opt to use the diapers and fold them down in case the umbilical stump stays and touches the cord. There are a few babies that start wearing the size 1 diapers from birth itself, this is why most hospitals have these size 1 diapers available in their pharmacy.