Fast-fashion retailer Zara found itself in the headlines last month after the first lady wore one of the company’s designs — a 2-year-old olive-green jacket emblazoned with the words “I REALLY DON’T CARE, DO U?” — on her way to visit immigrant children who had been forcibly separated from their parents.

The backlash was immediate. And although the incident may have been more about the first lady’s sartorial message than the actual garment, the world’s largest clothing company was once again in the middle of a firestorm, raising questions about why certain fast-fashion retailers — H&M, Topshop and Urban Outfitters, among them — repeatedly end up in the hot seat.

Fashion professors say the constant pressure to churn out new clothing makes it difficult to ensure proper oversight. Zara alone produces 20,000 designs a year, while its parent company, Inditex, manufactures roughly 1 billion items annually.

Sometimes, that leads to controversy. Zara last year faced criticism for selling a miniskirt printed with a cartoon character that resembled Pepe the Frog, a hate symbol used by white supremacists.

The Spanish chain has also apologized for selling striped pajamas for children with a yellow star on the breast that some said resembled concentration camp uniforms, and an embroidered handbag that included a swastika design. The retailer later pulled all three items from its shelves.

“Everything just has to happen so quickly,” said Abigail Glaum-Lathbury, a professor of fashion design at the School of the Art Institute of Chicago. “It’s like an assembly line — we hear a lot about the strenuous working conditions at factories, but design teams are under similar pressure. It’s not likely that anyone is saying, ‘Hey guys, let’s stop and consider the context and meaning of each item we put out.’ ”

And, she added, “without context, without history, you are bound to make really epic failures.”

Zara has a three-part process for vetting its products, according to Zara spokeswoman Amaya Guillermo.

The company uses an algorithm to scan each design for insensitive or offensive elements or language. Each piece of clothing is then reviewed by a global committee in Spain, where the company is headquartered, and later by local committees in each market where the item will be sold.

“These are huge, lumbering, out-of-touch multinational corporations,” said Elizabeth L. Cline, author of “Overdressed: The Shockingly High Cost of Cheap Fashion.”

Earlier this year, H&M faced backlash for an ad that featured a black child wearing a sweatshirt that said “Coolest monkey in the jungle.” The company apologized, pulled the shirt from its shelves and said it has created a new team devoted to diversity and inclusiveness. H&M did not respond to requests for comment.

Analysts say retailers are also increasingly relying on algorithms and sales data to determine what shoppers want.

The fact that Americans are spending less on clothing than they once did, even as the number of retailers continues to grow, is also leading some to cross the line between edgy and offensive.

“There’s such a need today to stand out — there is so much competition in the marketplace — that companies, designers, advertisers are all desperate to get attention,” said Milton Pedraza, chief executive of the Luxury Institute, a consulting firm in New York.

“And one way to do that is to say, ‘Let me see how far I can take this.’?”