World Rugby, the governing body for rugby union, yesterday issued new guidelines which will ban trans women from competing in elite and international women’s rugby. Trans women are biological males who identity as women.

The new policies cover international and elite women’s contact rugby, but World Rugby say that national rugby unions can be flexible in applying the new guidelines at the community level. Transgender men are still permitted to compete in men’s rugby.

The new guidelines were released following a months-long consultation and evidence review chaired by Dr Araba Chintoh. Dr Chintoh said that “We set out to determine whether it would be possible to maintain inclusion in contact rugby based on the available research and evidence and rugby’s unique context of combining strength, power, speed and endurance in a physical, collision environment. As we progressed through a comprehensive and inclusive review, it became clear that there are compelling evidenced safety considerations which we simply cannot ignore.”

World Rugby released a statement which said that, following months of debate and review of the existing scientific literature, “safety and fairness cannot presently be assured for women competing against trans women in contact rugby.” Documents released alongside the statement said that “biological males…are stronger by 25% to 50%, are 30% more powerful, 40% heavier, and about 15% faster than biological females.” These facts mean that there was a massively increased risk of injury if trans women continued to compete against women.

Some sports bodies have allowed trans women to compete against women so long as those trans women have suppressed their natural male levels of testosterone but World Rubgy’s review of the evidence showed that reducing testosterone only removed about 20% of the muscle and strength advantages enjoyed by biological males, and that research showed no loss in bone mass after 12 months of testosterone suppression in trans women. They concluded that “significant advantages for biological males remain after testosterone reduction.”

Whilst some have put forward the argument that the physiological advantages that trans women possess over biological women are simply part and parcel of sports, and that some people are simply better at sports than others due to their innate physical attributes, World Rugby totally rejected that line of argument in relation to trans women. They stated that the difference between men and women creates ”physiological differences that are so large that they create insurmountable performance advantages for the best males in almost all sports, along with associated risk factors for females in direct contact competition with them.” They added that if sport was not sex segregated “the outcome would skewed so far in favour of males that every champion, and indeed, every elite athlete, Olympic participant, and scholarship recipient, would be male, based on the fact that many thousands of men and boys are faster, stronger and more powerful than the very best women in almost every sporting pursuit and discipline every year.”

World Rugby Chairman Sir Bill Beaumont added: “Rugby is a welcoming and inclusive sport and, while this has been a difficult decision to make, it has been taken following comprehensive consultation and engagement and for the right reasons, given the risk of injury.”