The Trump administration’s reinstatement of a policy that bans U.S. foreign aid to agencies that provide abortion counseling abroad was a predictable move that could have unintended consequences, Stanford researchers say.

The move freezes funding to nongovernmental organizations that provide abortion services or discuss abortions as a legitimate  family-planning option. It revives what is known as the “Mexico City Policy,” so called because it was announced by President Regan in 1984 during a U.N. population conference in Mexico City. It’s a highly partisan policy, which has been implemented under Republican administrations and suspended by Democratic presidents.

From that standpoint, the move to revive the policy was no surprise, said Grant Miller, PhD, an associate professor of medicine at Stanford and core faculty member at Stanford Health Policy. But Miller’s research has shown that the policy actually appears to have the unintended effect of increasing, not decreasing, abortions in the developing world.

“The bottom line is that it doesn’t matter what you think about abortion and the morality and ethics of it,” Miller told me. “I don’t think either side of the disagreement would think a good policy is one that leads to an increase in abortions. Neither side wants to see more abortions.”

In 2011, Miller published a study with Eran Bendavid, MD, on the impact of the policy between 1994 and 2008 in sub-Saharan Africa, a region in which family planning services are heavily financed by U.S. foreign aid. Family planning agencies provide a range of family planning services, including contraception, so when their funding is cut, the availability of contraception declines, said Bendavid, the study’s lead author and another faculty member at Stanford Health Policy. This results in declining use of safe contraception and an increase in abortion rates, the researchers found.

“Sure enough, where you see this relative decline in use of contraception is where you see this uptick in abortion,” said Bendavid, an assistant professor of medicine. “Our theory of what is underlying this is this notion that when women have more restricted access to modern contraception, they rely on abortion. If the intention was to curb abortion, then what we observe is that cutting support to family planning organizations led to the  opposite effect.”

Miller followed that up with another study published in 2016 that focused on Nepal during the period when the government legalized abortion, making it more widely available. The policy change gave him the opportunity to test the idea of abortion and contraception as substitutes — i.e. that use of one method to limit family size reduces use of the other. In fact, as the number of abortions rose, use of contraception declined, he found.

“What is remarkable is that this is clear evidence on this interchangeable use that women make in use of contraceptives and abortion services,” Miller said.

In other words, women are trying to control the number of children they have and will use one or the other, depending in part upon what is most available. “If contraception is available, they won’t have to resort to abortion,” Bendavid said.

He said these results have subsequently been corroborated in other studies in sub-Saharan Africa.