Households across the globe look differently than they did 20 years ago, with women in most regions of the world marrying later, having fewer children and increasingly raising children in committed partnerships without getting married at all, according to a United Nations report released on Tuesday.

The report, which is published by the U.N. every five years, uses census data and other statistics from 197 different countries to examine the state of the world’s women in terms of health, education and fertility. Data in the report is meant to help policymakers address issues such as reducing the gender gap in education and increasing access to family planning — key issues in the U.N.'s efforts to help countries achieve gender equity and empower women and girls.

Worldwide, average fertility rates for 2010 to 2015, the years covered in the report, fell to an average of 2.5 children for every woman. That was a significant decrease from an average of three children per woman from 1990 to 1995. The report said the average age of marriage for women increased over the last 20 years by one year, to 25. The average age for marriage for men was 29, also an increase of one year in the same time period.

These changes are largely because more women are seeking out higher education, entering the work force later and achieving more economic independence as a result, the report said. Access to family planning services and contraception was also directly linked to declining fertility rates.

In certain regions of the world, fertility rates remain high, and the average age of marriage is young, particularly in areas of sub-Saharan Africa and South Asia. For example, the average fertility rate is 5.6 children per woman in Central and West Africa, versus about 1.6 children per woman in Eastern and Southern Europe, where rates are among the lowest. The average age of marriage for women in South Asia and sub-Saharan Africa is 21 and 22, respectively, versus 29 in developed countries, the report said.

While demand for contraception and family planning is lower in sub-Saharan Africa than in more developed countries, there is also a high unmet need for it among women who do want it, which contributes to high birth rates, according Francesca Grum, chief of the social and housing statistics division at the U.N.’s Department of Economic and Social Affairs.

In some parts of sub-Saharan Africa, for example, about 50 percent of women would like access to family planning including contraceptives, but only half of those women are able to get it. Worldwide, the report said, 145 million women of childbearing age who are married or in a relationship had some kind of unmet need for family planning in 2014.

Grum also said that while one of the U.N.’s development goals is to end child marriage, progress is slow — the number of women who married before they were 18 decreased by 5 percentage points over the last 20 years, to 26 percent in 2010. Child marriage rates were highest in South Asia, with 44 percent of women aged 20 to 24 getting married before the age of 18.

“That’s still unacceptable,” Grum said. “It’s still too high. We know that results in early pregnancies, and then they have limited opportunities in terms of education and career.”

Having children without getting married is increasingly common, especially in European and some Latin American and Caribbean countries, where living with a partner outside of marriage is gaining social acceptance.

In Uruguay, for example, 42 percent of women between the ages of 25 and 29 were involved in “consensual unions,” a rise from 16 percent in 1996. In Denmark and Finland, nearly 30 percent of women between the ages of 20 and 34 lived with their partners but were not married to them.

Birth rates outside of wedlock were particularly high in the Caribbean and Latin America where 85 percent of all births in Jamaica, 83 percent in Panama and Venezuela and 80 percent in Colombia were to unmarried women for the period 2000 and 2011.

The rate of childbirth outside of marriage is also rising fast among the 34 developed countries that are part of the Organization for Economic Cooperation and Development countries. Nearly 33 percent of children in those countries were born outside of marriage in 2007, the latest year for which data was available, compared to 11 percent in 1980.

Higher divorce rates, particularly in Latin America, have led to a rise in single-parent households headed by mothers, because women tend to be granted child custody, the report said. Single mothers with children are more likely to live in poverty than single fathers, as are elderly, widowed women, another group that is growing due to an aging population paired with shorter average lifespans of men.