By Emily Buchanan World affairs correspondent, BBC News

"In today's globalised world, goods and capital flow freely and receive more protection than people crossing borders" - that is the stark conclusion of a report by the UN's Population Fund.

The UNFPA urges governments to respect women migrants' rights

And those who have the least protection are the 95 million women and girls who make up half of all international migrants.

When it comes to policy making and discussions on migration, they are widely ignored, says the report.

In the UNFPA's latest State of the World Population study, executive director Thoraya Ahmed Obaid calls on governments to "recognise the contributions of migrant women and girls and respect their human rights".

The report says that women contribute billions in remittances sent back to their home countries, contributing a higher proportion of their low earnings than men, while working as cleaners, carers or waitresses.

The UN study cites one example of Bangladeshi women working in the Middle East sending home 72% on average of their pay.

While a great proportion of migrant women do better themselves and their families back home, millions are still vulnerable to exploitation and abuse.

Some women are trafficked and forced to work as prostitutes

The report says that domestic workers are rarely protected by labour laws or allowed to unionise. Many have been assaulted, raped, overworked and denied pay and rest days.

The worst area of abuse concerns the hundreds of thousands of female migrants every year who cannot find a legal way to travel abroad and resort to the "modern-day enslavement of trafficking", the UNFPA says.

Desperate for work, they then find themselves in debt and are frequently forced into sex work or sweatshops.

Ms Obaid says that "although awareness against trafficking is growing there is an urgent need to do more to end this terrible crime".

Two-way process

The issue of international migration is creeping up the global agenda and the UNFPA hopes that this report, coming just before next week's 192-country High Level Dialogue on International Migration and Development in New York, will put the spotlight on the issue of women migrants.

The complicating factor in addressing the abuses of migration is that policies need to change in both the sending and the receiving countries.

The report's authors argue that much more needs to be done to address poverty and discrimination in the sending countries, so fewer people want to leave, and that more emphasis must be placed on the rights of migrants in receiving countries.

The International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families has been in force since 2003, but still it has not been ratified by most developed nations.

One of the most worrying trends is that the intention to migrate is especially high among health workers surveyed in regions hit hard by HIV/Aids.

Young people aged 10 to 24 now make up a third of all migrants

When nurses decamp because of poor pay and conditions, patients suffer and health care systems crumble.

In 2000, twice as many nurses left Ghana as graduated. More than half of all nursing vacancies in Jamaica and Trinidad and Tobago were unfilled in 2003.

At the same time the demand for nurses from the ageing industrialised countries is projected to soar.

The report also highlights the growing trend of young people deciding to move countries. Those aged between 10 and 24 now make up a third of all migrants.

Developed countries with ageing populations benefit from this youthful migration, but because of their age young people are often denied opportunities to migrate legally and can also end up being exploited.

The overall message of this wide-ranging report is that the world needs to address the problems of migration urgently, as they are not just going to disappear.

Having doubled in the last 50 years, the movement of people across borders is likely just to keep growing.