We had this happen several times where a family would call back and state they could not tell if a diaper was wet.
Typically, they were using disposable diapers and it was in the first week of the baby’s life. We had these families bring their baby to be weighed to check if things were going well. Thankfully, in each instance, babies were doing well and gaining weight, but the diapers were so absorbent that they didn’t feel wet to the parents.
Once the baby was over a week old and their urine volume increased, families were easily able to tell when the diaper was wet. Sometimes it helps to check if they are heavier or warmer to the touch. This usually indicates they are wet. You can also use a cloth diaper—no trouble telling if they are wet. You can also use something that gets wet in a disposable diaper like: gauze, tissue, small piece of cloth or a handkerchief to name a few choices. These items will get wet and you will be able to easily tell if the disposable diaper is wet.