Does The Newborn Diaper Fit the One Size Cover?

The short version: No, they are completely different sizes

The Long version: The size and needs, of babies who are less than a month old and 6 lbs, and those who are 35 lbs and over 2 years old, are vastly different. The newborn cover is smaller and amount of hemp that is needed for an older baby simply wont fit in a diaper that will hold leaks or stop blowouts with newborns.