As global fertility rates continue to decline, even majority-Catholic and historically Catholic countries aren’t free from the demographic collapse, which increasingly threatens to shrink the populations of countries below the necessary rate of replacement. 

Global fertility has been falling for decades, with the problem often most acute in industrialized nations with higher standards of living, even while the fertility rates in many developing nations with strained resources, especially in sub-Saharan Africa, continue to climb. Many of the world’s most developed countries are well below the “replacement rate” of fertility — generally about 2.1 births per woman over her lifetime — needed to keep a population stable, according to data gathered by the World Bank.

In the U.S. the overall fertility rate in 2021 was about 1.7, falling to 1.6 two years later; in the U.K. in 2021 it was about 1.6; in Greece about 1.4. Japan and South Korea have some of the lowest birth rates in the world at 1.3 and 0.81 respectively. 

Catholic populations have for years been associated with high fertility rates, owing in part to the Church’s forbiddance of artificial contraception and its long-held teaching that children are, in the words of the Second Vatican Council, “the supreme gift of marriage.”

And yet fertility numbers below the replacement level can be seen even in countries with a majority Catholic population or with historically high levels of Catholics. A recent panel that took place at the Catholic University of America moderated by New York Times columnist Ross Douthat looked at the variety of reasons for this, which includes loss of religious faith and changing cultural values.

Some countries with high levels of Catholics are still reporting high levels of fertility: Angola, for instance, is more than 50% Catholic and reports a fertility rate of 5.6 — well above the global average. Paraguay, meanwhile, is about 90% Catholic and has a fertility rate of 2.5, which is above replacement level.

Yet other countries long known for high levels of Catholicism are nevertheless well below replacement levels: Poland, at more than 90% Catholic, has a fertility rate of 1.3; while Spain, at 75% Catholic, is even lower at 1.2. Mexico is more than 80% Catholic yet still falls below replacement level, at 1.8.

A National Bureau of Economic Research study from 2012 found that “strongly Catholic countries” in Europe at the start of the 1970s “had fertility almost a half child per woman higher” than surveyed non-Catholic countries. Yet by the end of the 20th century, those same Catholic countries had fertility rates considerably lower than non-Catholic countries.

The 2012 study argued that the decline could be attributed to the fact that the Catholic Church “retreated in the mid 1960s from providing a variety of family-friendly services,” including “education, health, welfare, and other social services,” thus making it more expensive to have children. Additionally, polling shows that large majorities of Catholics believe birth control is acceptable, while other data indicate large majorities of Catholic women are using some form of artificial contraception. 

Church leaders, meanwhile, have been sounding the alarm bell of declining fertility rates in recent years. 

The Vatican announced on Thursday that Pope Francis will speak at an event on Italy’s demographic crisis as the country’s birth rate sits at a historic low.

The Holy Father has in the past described the low number of births as “a figure that reveals a great concern for tomorrow.” He has criticized what he describes as the “social climate in which starting a family has turned into a titanic effort, instead of being a shared value that everyone recognizes and supports.”

Francis in 2022 also described cratering fertility rates as a “social emergency,” arguing that while the crisis was “not immediately perceptible, like other problems that occupy the news,” it is nevertheless “very urgent” insofar as low birth rates are “impoverishing everyone’s future.”

At a United Nations event this month, meanwhile, Archbishop Gabriele Caccia argued that contraception and population control are “not the key to sustainable development,” stating rather that it is “essential to guarantee that all men, women, and children are afforded the opportunity to actualize their full potential.”

In 2019, San Sebastián Bishop José Ignacio Munilla Aguirre warned of Spain’s “desolate panorama in terms of the birth rate,” a figure he said constituted “one of the most obvious signs of the crisis of values the West is suffering.”

Provisional data published by the Centers for Disease Control and Prevention (CDC) last month, meanwhile, showed that the fertility rate in the United States hit a record low in 2023, falling to just over 1.6 births per woman, a 2% decline from the previous year.