By Mary Ziegler
As Joanna Wuest writes, the role played by science in the LGBTQ+ movement “is at once a celebratory and cautionary story.” Something similar could be said of struggles over reproductive rights in the half century since the Supreme Court decided Roe v. Wade.
Today, after decades of staying on the sidelines, physicians have once again been at the forefront of struggles over abortion, launching a ballot initiative in Ohio, bringing lawsuits, and speaking against state criminal bans. Physicians’ investment in the struggle — and the scientific arguments they bring to bear — seem like a possible turning point in future struggles over reproductive rights and justice. After all, medical professionals have both special expertise and political capital that could make a difference at a time when disapproval of abortion bans is already high.
But history suggests that arguments based on science have played a far messier role in struggles over reproductive rights. As often as scientific evidence has advanced reproductive rights, abortion foes have used claims about scientific uncertainty to justify new restrictions — and have harnessed claims of biological difference to assert that there is no connection between sex equality and abortion.
Advocates for abortion rights have seen scientific claims as powerful in the past. In the 1960s and 1970s, they enlisted scientific expertise to demand the undoing of nineteenth-century criminal laws. They stressed the safety of new abortion techniques, the risks of illegal procedures, and the importance of deferring to physicians, who knew more about what their patients needed than prosecutors, politicians, and judges. Roe itself embraced science, assigning the abortion right partly to physicians, and dedicating much of the opinion to the discussion of physicians’ views of abortion.
But scientific arguments were hardly a silver bullet for abortion rights supporters. Antiabortion activists had long made scientific claims of their own about fetal personhood, arguing that fetology and genetics unmistakably established that an unborn child was human — and that any biological human was entitled to equality and due process of law. And when fetal personhood arguments failed to gain traction in the 1970s, antiabortion groups did not give up on scientific arguments, instead seeking to produce evidence questioning the safety of abortion.
The more the Supreme Court discussed the connection between abortion and sex equality, the more abortion opponents invested in strategies centered on scientific uncertainty. Following the Supreme Court’s 1992 decision in Planned Parenthood v. Casey, antiabortion groups seized on part of the opinion suggesting that women had relied on the availability of abortion to achieve a more equal citizenship. Convinced that the Court would never reverse Roe unless the justices believed that women did not need abortion, right-to-lifers set out to create uncertainty about whether abortion harmed those who chose it. Antiabortion groups founded groups to study what they called post-abortion syndrome and proposed model laws requiring physicians to report that abortion increased the risk of breast cancer. When other research undermined these claims, antiabortion groups insisted that caution was warranted: if anyone believed the science to be uncertain, why not err on the side of protecting women from abortion?
This strategy became especially salient during the fight over dilation and extraction, a procedure that the antiabortion movement called partial-birth abortion. When Congress passed a federal law banning the procedure in 2003, the bill did not include a health exception. There was no need for one, lawmakers insisted, because antiabortion physicians and experts disagreed about whether to mandate such an exception. This definition of scientific uncertainty — one inextricably linked to constitutional conflict and political polarization — shaped litigation at the Supreme Court, which upheld the federal Partial-Birth Abortion Ban Act in 2007. The Court in Gonzales v. Carhart reasoned that in conditions of scientific uncertainty, lawmakers should have more latitude to regulate.
Separating claims about equality and morality from scientific contentions became even harder after the transformation of the Supreme Court during the presidency of Donald Trump. After a reconfigured Court agreed to hear a challenge to a Mississippi fifteen-week ban, antiabortion commentators tried in various ways to counter the claim that the Equal Protection Clause limited the state’s power to ban abortion: disputing evidence that abortion access had helped women improve educational or career outcomes, for example, or claiming that abortion damaged women’s psyches and bodies. Some simply turned back to biological determinist claims that the movement had made since the 1960s: pregnancy is not a disease, and laws that prohibited abortion at most had to do with biological differences, not invidious stereotypes.
The latter claim gained influence in the Dobbs decision itself. In a brief paragraph, the Court rejected a sex equality basis for the abortion right, suggesting that the Court had already concluded in Geduldig v. Aiello (1974) that discrimination on the basis of pregnancy was not sex discrimination. “The regulation of a medical procedure that only one sex can undergo,” the Court explained, “does not trigger heightened constitutional scrutiny unless the regulation is a ‘mere pretex[t] designed to effect an invidious discrimination against members of one sex or the other.’” Women, Dobbs reasoned, were simply born this way, and laws that regulated based on their reproductive capacity raised no concern under the Equal Protection Clause.
After Dobbs, conservative groups have made similar arguments in defending laws banning gender-affirming care for minors and excluding such care from Medicaid and other insurance programs. At the same time, antiabortion groups have mobilized arguments about ingrained biological differences in launching a new campaign for personhood, with leading groups like Students for Life insisting that biological evidence compels the recognition of equal fetal rights under the Fourteenth Amendment.
Wuest powerfully shows that scientific arguments can underwrite campaigns for progressive social change. But as the past fifty years of struggle over abortion have shown, those pushing scientific claims to the center of debate might be careful what they wish for.
Mary Ziegler is the Martin Luther King Jr. Professor of Law at the University of California, Davis School of Law.
