Efforts to ensure women's access to family planning, and to reduce the number of maternal and child deaths, have achieved significant results over the past 20 years, but progress has been unequal and fragmented, according to the UN.

The number of women dying in pregnancy or childbirth has dropped by almost half, and total global fertility rates have fallen by nearly a quarter. But access to health services remains patchy, particularly in rural areas of Africa, Latin America and parts of Asia, and sex discrimination remains deeply entrenched.

"A belief in, and commitment to, gender equality is not universal, and gender-based discrimination and violence continue to plague most societies," says a report by the U N population fund, the UNFPA, which reviewed progress against commitments made at the International Conference on Population and Development (ICPD) in Cairo in 1994.

The wide-ranging study, which examines progress in more than 170 countries that signed up to the Cairo programme of action, found that people with disabilities, those from indigenous groups, and those who are lesbian, gay, bisexual or transgender have also faced persistent discrimination.

It says governments had talked the language of gender equality by introducing laws to ensure women's rights were protected, but had been selective about their implementation.

One in three women has experienced physical and/or sexual abuse, and in some places men openly admit they have raped and face no consequences. In no country are women equal to men in political or economic power, it says.

"While the core message of the ICPD was the right of all persons to development, the rise of the global middle class has been shadowed by persistent inequalities both within and between countries. While we have made important gains in health and longevity, these gains are neither equally shared, nor accessible for many," says the report.

The outcome of the ICPD in 1994 was considered groundbreaking. It was the first time member states agreed that equal rights and universal access to sexual and reproductive health services were essential for sustainable development.

Discussions about population control moved from slowing growth rates through family planning policies to look instead at ways to improve the lives of women and girls more broadly, emphasising their social and economic empowerment, women's right to control their bodies and their fertility through access a range of modern contraceptive methods, along with universal access to education for girls.

The outcome document contained more than 200 recommendations, with a deadline of 2015. It sought to address the environmental impact of population growth and emphasised the elimination of all forms of violence against women, the reduction of maternal mortality rates, and an end to sex discrimination. It also touched on migrants' rights to services and the support of indigenous groups.

The UNFPA review, which pulls data from global surveys, country implementation plans, regional reviews and conferences, will feed into high-level discussions about the new targets that will follow on from the millennium development goals when they expire next year. A working group has been charged with drawing up a set of sustainable development goals and is due to present to the UN general assembly in September. This follows post-2015 recommendations made by a UN high-level panel last year.

Babatunde Osotimehin, executive director of the UNFPA, said the report would "give us leverage to take things to the next level, where women and girls and young people are central to the next development agenda".

But he added that inequality between and within countries was "excluding enormous numbers of people from progress. Inequality is a major issue and has become evident in the period of the review. Inequality is affecting the pace of growth, and quality and dignity of growth. Even though we have reduced maternal mortality, in the poorest communities … there are still very high maternal deaths. We still have 1,000 women dying per 100,000 live births because of poverty and lack of access [to services]. There are things Cairo committed to that are not happening."

More than 200 million women who wanted family planning services could not access them, he said, adding that it was important women had a range of modern contraceptives to choose from, and the freedom to choose what method they wanted to use. Osotimehin said he was recommending that governments provide four or five types of contraceptives, and ensure regular supplies.

The UNFPA report calls on states to provide emergency contraception and universal sex education in schools in an effort to eliminate the need for abortion, a procedure not explicitly mentioned in the ICPD Cairo document. The report also calls on governments to take concrete measures to reduce unsafe abortions.

One of the major issues that comes out of the review is how to support a growing number of young people, said Osotimehin. Globally, there are an estimated 1.2 billion adolescents, around 90% living in developing countries. Osotimehin said governments had a chance to capitalise on the potential of young people for future development progress, but this would come at a price.

"The price is governments must invest in their education, including sexuality education, in access to services, including contraception, and we must have skilled development, [giving them] access to credit and to political participation," he said. "We are talking to many of our colleagues about how to make sure the issue of young people is central in the development agenda we are working to formulate in the post-2015 development framework."

Progress on ICPD will be discussed at the UN Commission on Population and Development in April, and at the UN general assembly later in the year.