It's the universal trend that has stayed fashionable for centuries.

Could blue jeans really be fading away? NBC reports the 2013 sales of jeans in the U.S. dropped 6 percent. That might not seem like a huge percentage, but the news outlet spoke with a chief industry analyst who said "It's rare for denim to take such a dramatic drop."

Big-name jeans designer Levi Strauss & Co. - which claims it created the first ever pair of blue jeans all the way back in 1873 - has been hit hard by this decline. In April, the denim company revealed its profits for the first quarter of this year had dropped 53 percent compared with 2013's first quarter. One month earlier, it announced 800 jobs would be cut - a move that would save Levi Strauss & Co. between $75 million and $100 million in costs.

So, what are people trading their jeans in for? CTV spoke with retail analyst Dough Stephens who says the choice is resulting from customers wanting to be comfortable.

"Yoga wear is having a huge impact. ... New fabrics, new designs, new and more comfortable fashions for people to wear more casually and to work."

Part of the reason for the decline could be because the price of a pair of jeans has increased dramatically since more designers with big names started selling denim. A pair of 7 For All Mankind jeans for both men and women start at around $200. And J Brand sells a pair of women's skinny jeans for a whopping $285. This is compared to clothing companies like American Apparel who are selling yoga pants and leggings for as low as just $17.

Other denim retailers seem to be taking note of these cheaper costs for yoga wear and are trying to gain customers by having them spend less money. Money Magazine says all jeans sold at American Eagle Outfitters are under $30. And Wal-Mart has come out with rollback prices on its denim, bringing specific pairs of Levi's down to just $13.

But don't throw out those pairs of jeans just yet in favor of those oh-so-comfy yoga pants. NBC spoke with the editor in chief of Marie Claire, who said denim could be making a comeback.

"For this fall, fashion has fallen in love with denim. There was so much denim coming down the runways. ... Yes, people are wearing yoga pants, but no one will ever stop wearing jeans."