The Women's Six Nations has been postponed until the spring at the earliest as the COVID-19 pandemic continues to affect the world's sporting calendar.
The Under-20s championship has also been postponed with the Six Nations confirming in a statement on Wednesday that further details on both tournaments will be released by the end of January.
Both tournaments normally follows the same calendar as the men's competition which the Six Nations confirmed will start on Feb. 6 in Rome with Italy vs. France.
"We are fiercely committed to the promotion and development of rugby at all levels, particularly the women's game where we see such exciting opportunity for growth," Six Nations CEO Ben Morel said in a statement.
"This is not a decision that we rushed into and we are confident that in looking at a new later window, we will be in a far stronger position to deliver two fantastic tournaments, delivering exciting rugby for fans, and ensuring the safest possible environment in which to stage them for our players."
England, the reigning women's champions, are the only professional team in the tournament with France semi-professional. The other four teams mainly consist of players who are considered "amateurs" which has created issues over testing, bubbles and travelling.
Three fixtures in the 2020 tournament were cancelled and never rearranged due to the ongoing pandemic.
The 2021 tournament is particularly important to teams with the World Cup happening in New Zealand in September.
Ireland, Scotland and Italy have yet to qualify for the tournament and the Six Nations fixtures may aid their qualification.
The European qualification tournament for the Women's World Cup was indefinitely postponed in November due to COVID-19 travel restrictions.
The event was due to be contested by the three Six Nations teams and the winner of the postponed Rugby Europe Women's Championship, with the victors qualifying for the World Cup.
"This is disappointing news that we fully accept is in the best interests of everyone involved," Irish Rugby Football Union's director of women's and sevens rugby Anthony Eddy said in a statement.
"Our training programme is reviewed on an ongoing basis to adapt to ever changing circumstances and our players have demonstrated a commendable attitude and resilience in this regard while adhering to strict safety protocols.
"We will also continue to work with World Rugby to ensure our Rugby World Cup 2021 qualification games can take place in a timely and safe manner."