Women are doing significantly more domestic chores and family care, because of the impact of the pandemic.
Employment and education opportunities could be lost, and women may suffer from poorer mental and physical health.
The care burden poses a "real risk of reverting to 1950s gender stereotypes", Ms Bhatia says.
Even before the pandemic, it was estimated women were doing about three quarters of the 16 billion hours of unpaid work that are done each day around the world.
In other words, before coronavirus, for every one hour of unpaid work done by men, three hours was done by women. Now that figure is higher.
UN Women warns that the ripple effect from having fewer working women will be dire on not only women's wellbeing but their economic progress and independence.
Women's unpaid work often covers the cost of care that sustains families, supports economies and fills in for the lack of social services, but it's rarely officially recognised as work.
Women who do the bulk of unpaid work will either have less time to engage in paid labour, or work longer hours, and often face financial insecurity either way.
The UN is calling on governments and businesses to acknowledge that unpaid work exists and implement measures such as extra family leave, or extra paid leave, and keeping childcare centres open.