New York state, Minnesota and Washington, D.C., all have pending legislation that would legalize the practice of commercial surrogacy—paying someone to have a baby on your behalf. Reproductive technology has made surrogacy possible since the 1980s, but it remained relatively rare until recent years as the technology improved and the legalization of same-sex marriage increased the number of childless couples eager to have children.

The Catholic Church has long opposed surrogacy, whether paid or unpaid. Nowadays, with increasing pressure for the legalization of paid surrogacy, the church has found itself with an unfamiliar ally: feminists.

The Catholic Church and women’s rights groups are accustomed to clashing over policy matters involving contraception and abortion. But now the two camps can often be found working hand in hand when it comes to protecting both women and children from being exploited in the growing and largely unregulated fertility industry.

Recent episodes involving surrogacies gone wrong have shown that there is reason for concern. Most prominently, the plight of “Baby Gammy” caused world-wide headlines this summer when an Australian couple rejected the boy, born with Down syndrome, but kept his healthy twin sister after a Thai woman they hired gave birth.

Catholic feminist Lucetta Scaraffia took to the pages of the Vatican’s official newspaper, L’Osservatore Romana, to describe the Baby Gammy story as evidence of the “throwaway culture” that Pope Francis has decried. “We should not be surprised,” she wrote, “if parents who have ordered a baby and rented a woman’s womb refuse it at birth if it is not healthy and perfect.”

In the U.S., laws vary widely regarding surrogacy, paid or unpaid. Some states, like Arizona, ban any such arrangements, but others, including Nevada and New Hampshire, allow them but add stipulations, such as restricting payment to covering expenses (often a euphemism for compensation).

The ethical concerns around surrogacy are such that in August 2012 New Jersey Gov.Chris Christie vetoed a bill aimed at legalizing paid surrogacy. He had been encouraged to stop the legislation by Catholic groups and by feminists such as Kathy Sloan, a board member of the National Organization for Women. (Ms. Sloan was also a special consultant to the Center on Bioethics and Culture, where I work.) Writing in the New Jersey Star-Ledger days after the veto, Ms. Sloan said: “Women’s health and human rights advocates are popping champagne corks all over the country.”

Why are feminists and the Catholic Church finding common ground? Too often paid surrogacy appears exploitative. Women who serve as surrogates tend to be poor and are tempted by the fees even though they’re taking on a nine-month, 24-hour, seven days a week physical and emotional commitment. For $25,000—a common surrogacy fee—the arrangement comes out to less than $4 an hour.

Women who serve as surrogates also may not consider the health risks—not just of pregnancy itself, but also of undergoing the implantation of a donor egg. There have been no long-term scientific studies of the risks from hormones given to surrogates to foster egg production or implantation, raising concerns about how much informed consent such women are able to give.

Then there is the matter of what happens to the children of surrogacy, not just those in tragic situations like that of Baby Gammy. An unsettling aspect of surrogacy is its severing of the natural maternal bonding that takes place during pregnancy. A prominent June 2013 study in the Journal of Child Psychology and Psychiatry found that children born through surrogacy are at great risk of adjustment difficulties and psychological problems. There are no long-term studies gauging how young adults conceived through surrogacy are faring, but the anecdotal evidence from such children’s countless blog posts and interviews suggest that many are wary of the very practice that allowed for their conception.

Leaders of the Pro-Choice Alliance for Responsible Research, writing online in April for the reproductive-health publication RH Reality Check, urged serious consideration regarding surrogacy: “Having insisted so powerfully on women’s rights, how do we ensure that we are not pitting one woman’s rights and well-being against another’s?”

Religious objections to surrogacy come not just from the Catholic Church. Earlier this year, before Louisiana Gov. Bobby Jindal vetoed a bill that would have legalized surrogacy contracts (paid or unpaid), he was encouraged to stop the law by Russell Moore, president of the Southern Baptist Ethics and Liberty Commission. Mr. Moore wrote: “Surrogacy [treats] women and children essentially as objects of commerce. Ultimately, it exploits women’s bodies and children’s lives. This is not the place for laissez-faire bioethics.”

In a time of such political gridlock and tension over the role of religion in this country, these shared demands for serious scrutiny of the practice of commercial surrogacy is a welcome cause for celebration—be it sacred or secular.

Mr. White is the director of research and education at the Center for Bioethics and Culture.