It’s not surprising that fewer disposable diapers were sold last year, given that the birth rate has been falling since 2007, with a 4 percent decline from 2007 to 2009, according to the CDC’s National Center for Health Statistics, and the trend is continuing.

Advertising Age has reported that, even as sales of disposable diapers dropped about 9 percent, during the same time frame, diaper cream and ointment sales rose by 2.8 percent, presumably because more babies were getting diaper rash.

Besides having fewer babies to diaper, it turns out that parents were also changing their babies less frequently. American babies, according to 2010 research by Procter and Gamble,were changed on average 6.3 times a day. Japanese babies were diapered 6.45 times daily, and babies in India were changed 9.03 times a day.

Whether it’s due to economic concerns or improvements in diaper absorbency that make more frequent changes less necessary, there are ways that parents can protect their baby from diaper rash.

“Diapers are now more absorbent, and you don’t have to change as often,” said Dr. Tanya Remer Altmann, a pediatrician in Los Angeles, an assistant clinical professor at UCLA Medical Center and associate medical editor of “Caring for Your Baby and Young Child: Birth to Age 5” (published by the American Academy of Pediatrics). “With the economy, some parents may be stretching the diapers longer.”

Even so, cautioned Dr. Altmann, parents should be doing what they can to prevent diaper rash.

“Parents should change the diaper after every stool,” she said. “I like to put a diaper ointment on with every diaper change. If you’re trying to stretch the diaper, use diaper ointment and apply it at every change .”

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