The tight U.S. economy has turned even essential items into luxuries. Now consumer-goods companies are seeing something they thought would never come to pass—parents are buying fewer diapers, Dow Jones Newswires reported Tuesday.

Spending on children has traditionally held steady in times of recession, including the most recent one, with parents sacrificing other items rather than scrimping on their children's hygiene or happiness. But as the economy continues to sputter, recent data show diaper sales are slowing and sales of diaper-rash ointment are rising.

The volume of diapers sold in the U.S. slipped one percent in the four weeks ended Sept. 4 from a year earlier, extending a string of similar or steeper declines stretching back to August 2010, according to Consumer Edge Research, whose retail-sales tracking does not include Costco Wholesale Corp. or Walmart Stores Inc. Dollar sales fell nearly three percent, indicating parents are both cutting back and trading down to cheaper private labels.

Dollar sales of diapers in the four weeks fell four percent at Huggies maker Kimberly-Clark Corp. Procter & Gamble, maker of Pampers and Luvs, saw dollar sales drop 2.5 percent. Even generics were down, with sales of private-label diapers slipping 0.5 percent.

The U.S. birth rate has declined since 2007, and it is not clear how much of the drop in diaper-buying is due to penny pinching and how much results from fewer kids. Changing technology— more absorbent diapers, for example—also make comparisons difficult. Finally, the cohort being surveyed is always changing because parents buy diapers for a few years and then move on.

Still, Consumer Edge Research analyst Javier Escalante sees economic pressure behind the data. "This has never happened in this country before—this is a very rare circumstance," he said, adding that the fact that people are having fewer babies is itself a strong indicator that the economy is influencing parental behavior. "That's a huge decision."

Meantime, sales of diaper-rash ointment have increased eight percent over the past year, according to market-research firm SymphonyIRI. Analysts and pediatricians said the higher sales likely reflect either less frequent changes or a shift to lower quality diapers.

Most pediatric clinics do not keep statistics on benign conditions like diaper rash, but doctors in poorer areas say they see the long-stumbling economy starting to take a clear toll on children's health.

Anjali Rao, a pediatrician at Northwestern Memorial Physicians Group in Chicago, said she has seen a five percent to 10 percent spike in diaper-rash cases this year. Daniel Taylor, a pediatrician at St. Christopher's Hospital for Children in Philadelphia, said he and his colleagues have heard from a growing number of parents that they must choose between buying diapers and paying for food and heat.

"We're definitely seeing major effects of the economy: Diapers are very expensive, and the longer you sit in a dirty diaper, the more likely the chances of an infection," Taylor said.

Click here to read more.