Strides continue to be made for women's rugby, with the 2025 event expanding to 16 teams.
The decision to add another four nations to the World Cup comes as the women's game continues to develop. Females account for 28 per cent of the global playing population of rugby union.
World Rugby chairman Bill Beaumont has called it a milestone moment for the sport.
"Women's rugby is the single greatest opportunity to grow the sport globally," he said.
"In 2017, we set out an ambitious eight-year plan to accelerate the development of women in rugby, with a core pillar focusing on high-performance competition and an ambition to improve and expand the number of teams competing in pinnacle events.
"We have seen in recent years that more teams are making a statement at international level and unions are continuing to develop their women's high-performance programmes.
"This is a milestone moment for the women's game. Expansion of the Rugby World Cup opens additional aspirational and inspirational playing pathway opportunities for unions at the highest level of the game and creates added incentive for unions worldwide to continue to invest and grow in their women's programmes."
The changes unfortunately come too late for the World Cup which will be held in New Zealand next year.
However, the 2021 World Cup will see the inclusion of a quarter-final phase to the competition for the first time ever.
Previously, teams which advanced out of the pools went directly into the semi-finals.
The process for the 2025 World Cup begins in February next year, with a host to be selected in May 2022.