Fit is the next frontier in baby diapers

Coterie now sells sizes from premie through size 7, with graded elastic tension calibrated to weight rather than age. It's a small change on paper and a large one in practice — it acknowledges that the diaper aisle has been quietly optimised around a narrow band of infants.

The commercial logic is real. Preterm birth rates in the US remain stubbornly above 10%. High-percentile babies routinely age out of a size months before the marketing suggests. And families of children with developmental delays often need diapering products well beyond the toddler window, in sizes that mainstream brands abandon.

Expect the next entrant to make "fits your baby, not the average baby" an explicit brand promise.