The increased use of contraception in many countries is not because more women at any moment want to delay pregnancy or have no further children. Instead, it is because contraception is helping more women achieve their childbearing goals.
This is the overwhelming conclusion from a study of national survey data from 59 low- and middle-income countries around the world.
Results showed that 85-90% of the change in contraception use is attributable to meeting the prevalent demand for reproductive control, versus only 10-15% attributable to an increase in the fraction of women who want to avoid pregnancy.
"Contraception use is increasing because women are more successfully carrying through on their preferences, achieving what they want. It's not due to large increases in the proportion of women who want to avoid pregnancy," said Mobolaji Ibitoye, lead author of the study and postdoctoral scholar at The Ohio State University's Institute for Population Research.
The rise in use of modern contraceptives in low- and middle-income countries over the past few decades has sparked a long-running debate on whether the increase is due to women wanting fewer children or not, said John Casterline, co-author of the study and professor of sociology at Ohio State's IPR.
One of the most surprising things about this new study is how definitively it answered that question, Casterline said.
"The results are overwhelming - it is not even a close call. It is a clear refutation of the view that contraceptive use has been driven primarily by reductions in demand for children," he said.
The study was published June 21, 2022 in the journal Studies in Family Planning.
The researchers analyzed five decades of data (1970s through 2020) from five major survey programs that involved women of reproductive age in 59 low- and middle-income countries. The surveys, which included the World Fertility Surveys and the Demographic Health Surveys, were done in countries in Africa, Latin America and the Caribbean, and Asia.
The study used at least two surveys from each country conducted at least eight years apart, which asked women about their contraceptive use and whether they wanted a child or another child.
Most of the surveys asked women who wanted to have a child how long they wanted to wait to get pregnant. That allowed the researchers to separate women into those who wanted a child soon, wanted one later, or did not want another child.
The researchers conducted statistical analyses to determine how women's use of contraception was linked to their preferences to have (or not have) children over time.
If changes in women's desire for children were causing the increase in contraception, then increases in contraception use should be linked to increases in the number of women who say they no longer want to have children over time. But that's not what the researchers found.
With few exceptions, similar results were found in countries all over the world.
The researchers also took into account the number of children women in the surveys already had to see how that fact affected the link between contraception use and desire for more children. Results showed it did not have major effects.
"About 10-15% of the increase in contraception was actually in women who said they wanted to have children soon, in the next two years," Ibitoye said.
"This is another piece of evidence refuting the claim that contraception use is increasing due to decreased desire for children."
Researchers often talk about the "contraceptive revolution" that came with the introduction of new contraceptive technology in the 1960s, including the birth control pill and the inter-uterine device or IUD, Casterline said. This research helps define what that revolution was all about.
"The revolution is that women can now carry through on what they want because of modern contraceptives," he said.
"The fraction of women who want to avoid pregnancy has not changed substantially. Instead, it's greater success in controlling when and how many children they have. It's an important global health achievement."
