Women and girls now make up half of all international migrants, totalling 95 million, a UN report says.
Women migrants play "a vital role" in supporting families at home
The report urges better protection of a population that it says is more vulnerable to abuse and trafficking.
It also says more young people are deciding to move countries, but because of their age cannot migrate legally and are also at risk of being exploited.
The economy of developed countries and their ageing populations benefit from migrants despite perceptions, it says.
This year's State of World Population report, entitled A Passage to Hope: Women and International Migration, is released by the UN Population Fund.
Migrant women send an estimated $232bn (£149bn) in remittances back to their home countries last year, says the report.
Remittances are the second largest source of external funding for developing countries after Foreign Direct Investment (FDI), it says.
Although women tend to send less overall than men as they earn less, studies show they send a higher proportion of their earnings to their families back home, the report says.
But the estimate does not take into account funds transferred through informal channels.
As domestic workers on low pay, they are rarely protected by labour laws and are not allowed to unionise.
Many have been assaulted, raped and overworked, the report says.
"This report calls on governments and individuals to recognise and value the contributions of migrant women, and promote and respect their human rights," says UNFPA Executive Director Thoraya Ahmed Obaid.
"There is an urgent need for stronger co-operation between countries to make migration more safe and fair. And there is a dire need for greater action to address the lack of opportunities and human rights violations that lead many women to migrate in the first place."
Young people aged 10 to 24 now account for about a third of all international migrants.
They take the most menial jobs in developed countries and constitute a growing share of highly-educated skilled labour.
Evidence shows that certain prejudices about migrants in Western countries are by and large ill-founded, the report says.
These include complaints that immigrants take locals' jobs, depress wage levels and are a burden on the social welfare system.
"Empirical evidence to support each of these complaints is weak or ambiguous - at least at the aggregate level," the report says.
It also points to the high numbers of health workers planning to migrate from regions hit hard by HIV and Aids - 68% of those surveyed in Zimbabwe and 26% in Uganda expressed a desire to leave their countries to work abroad, according to recent studies.
At the same time, the demand from the ageing industrialised countries is projected to soar, the report says.
The report comes ahead of next week's high-level meeting of 192 countries on international migration and development in New York.