Tennis great Serena Williams marked International Women's Day with an article in Fortune magazine urging women to "band together and fight for what's fair" as they juggle family and professional life.
Williams criticised the ranking system that left her with no seeding at last year's French Open after her return from maternity leave and suggested it precipitated an injury that eventually forced her to pull out of a fourth-round meeting with Maria Sharapova.
"When I returned to tennis from maternity leave, I was penalized for taking time off: my ranking dropped from No 1 in the world to No 453," the 23-time Grand Slam champion wrote.
"That required me to face tougher competition earlier in the French Open, which led to a pectoral injury that forced me to drop out.
"I fought hard personally, making it to the Wimbledon final shortly after, but I also fought hard publicly against the biased ranking system.
"We must stop penalizing women when they return to their careers after having children."
The WTA has already taken steps to give women returning from maternity leave or injury a protected ranking under new rules that also assure them of a first-round match against a non-seeded player in regular tour events.
The Grand Slam tournaments are free to decide their own seeds, as officials at Wimbledon did last year in seeding Williams 25th.
Williams has yet to win a tournament since returning to competition six months after giving birth to daughter Alexis Olympia in September of 2017, although she reached the finals last year at Wimbledon and the US Open.
Now ranked 10th in the world and seeded 10th in the prestigious combined WTA and ATP Masters tournament in Indian Wells, she was set to face another former world number one, Victoria Azarenka, in the second round on Friday.
It will be the first meeting between the longtime rivals since both became mothers.
Azarenka has tumbled down the rankings in the wake of the birth of her son Leo in December 2016 and a messy custody battle that limited her ability to travel to tournaments.
Williams cited a SurveyMonkey survey in which one of three women respondents said they felt they had to hide their emotions at work.
"This double standard is seen in the board room and on the tennis court. Women are deemed 'emotional,' 'hysterical,' or 'aggressive' while men who behave the same way face no such consequences," she wrote — an issue that some thought influenced chair umpire Carlos Ramos when he dramatically penalized her in the US Open final last year.