The Guinness World Records (GWR) plans to review its guidelines to "reflect the world we live in',' after a nurse was denied a record for not wearing a dress during the London marathon.
During last week's event, Jessica Anderson completed the 42.2km race in 3h 8m 22s, beating the previous record by 32 seconds.
But the GWR rejected her application before the race, saying her scrubs with trousers were "too much like a doctor's uniform", and their rules stipulated that a nurse's uniform must include a blue or white dress, a white pinafore apron and a traditional white nurse's cap.
The news prompted a social-media backlash from nurses, who've shared pictures of their real-life uniforms - including trousers - using the WhatNursesWear hashtag.
Although GWR told Anderson in February that she had missed the deadline for costume submissions, the organisation has now announced that her record will be reviewed.
"We're aware of the news surrounding Jessica Anderson's attempt for the fastest marathon dressed a nurse at this year's London Marathon," GWR said in a tweet.
"Guinness World Records takes the matters of equality and inclusiveness very seriously,
"I want to ensure all concerned that we have recognised the need for an immediate review of this attempt, and the fastest marathon dressed as a nurse category and associated guidelines, which we will begin as a priority.
"We are also committed to consistent reviews of all record categories to ensure they reflect the world we live in today."
Ms Anderson said she was stunned when she learned her outfit didn't meet the criteria.
"Their definition is just so outdated," Anderson told Runner's World magazine. "Some of the nurses I work with do wear dresses, but mostly we wear scrubs or a tunic and trousers.
"I've certainly never seen a male nurse wearing a dress to work. I'm sure Guinness World Records don't intend to cause offence, but it would be nice if they decided to revise their criteria instead of reinforcing old gender stereotypes."
Anderson, who works at the Royal London Hospital, raised more than £2,200 (NZ$4375) for Barts Health National Healthboard Service Trust.
The official world record for a woman running a marathon in a nurse's uniform is held by Sarah Dudgeon, who set a time of 3h 8m 54s in 2015.