A new report from the U.N. Population Fund (UNFPA) says 40 percent of all births in the United States occur outside of marriage, an increase from 10 percent in 1970.

The data show births outside marriage in the European Union (EU) are up even greater.

“The data show such births in the U.S. and EU are predominantly to unmarried couples living together rather than to single mothers,” Bloomberg reports.

Michael Hermann, UNFPA’s senior adviser on economics and demography, told Bloomberg the EU likely has even more out-of-wedlock births than the U.S. because its member countries provide greater amounts of welfare and public health funding in their socialized medicine programs. Unwed parents are also provided with tax incentives, Hermann said.

Kelly Jones, director for the Center on the Economics of Reproductive Health at the Institute for Women’s Policy Research, reportedly said the data show cultural and religious norms about women and marriage have changed, and women are starting families later in life. In the U.S., the average age a woman has her first child is now 27, according to the data, up from 22 in 1970.

“Women are claiming their ground professionally,” Jones said. “Delaying motherhood is a rational decision when you consider the impact it can have on your career, and that’s contributing to this trend.”

The marriage rate has also declined in the U.S., according to the U.S. Census Bureau, as the number of cohabitating adults has risen. In addition, the U.S. fertility rate plummeted last year to a record low.

John Santelli, professor at Columbia’s Mailman School of Public Health, told Bloomberg the traditional culture of the West “has been reversed.”

“Cohabiting partners are having children before getting married,” he said. “That’s a long-term trend across developing nations.”

Hermann said the trend in the cultural shift will continue.

“We can’t go back to ’50s,” he said.

UNFPA is the largest international provider of sexual and reproductive health services – which include abortion. The U.N. agency has been linked to the support of population control programs such as China’s coercive abortion “one-child policy.”

Soon after his inauguration in 2017, President Donald Trump signed an executive order that reinstated and updated the “Mexico City Policy,” thereby ending UNFPA’s U.S. funding because of its support and funding of abortion.