Originally uploaded at SSRN.


The Supreme Court has never justified the conclusion that the Constitution bars any substantial regulation designed to protect fetal life prior to viability. No majority opinion has ever offered a rationale for the viability rule, and the arguments recited in non-majority opinions are either conclusory or fail to distinguish viability from earlier lines that might be drawn. The most coherent academic attempt to justify the rule — Professor Laurence Tribe’s argument that a woman can “transfer nurture of [a viable] fetus to other hands” — rests on the erroneous assumption that a pregnant woman can arrange for premature delivery of any fetus that has crossed the viability threshold. The viability rule is arbitrary because the capacity of a fetus to survive outside the womb says nothing about the value of the fetus from the standpoint of the state or the burden of pregnancy on the mother, the two interests the rule purports to balance. The arbitrary character of the viability rule is highlighted by evidence that viability can vary for similarly-situated fetuses based on race, gender and irrelevant behavioral and environmental factors. This article contends that the viability rule provides too weak of a constitutional foundation to justify striking down all substantial abortion regulations twenty weeks after fertilization, when the risks of abortion outweigh the risks of childbirth.

Over a third of the states in recent decades have enacted legislation restricting abortion after 20-weeks’ gestation. The United States House of Representatives has twice passed a federal 20-week bill and a number of presidential candidates have expressed support for such legislation. Since some fetuses at 20 weeks will be previable, such legislation offers an opportunity to revisit the duration of abortion rights. This article advances four arguments for the constitutionality of a 20-week statute, including three based on current case law or minor modifications to current case law. First, the risks of late-term abortions are so significant that most providers will not perform the procedure after 20 weeks’ gestation. A state should be allowed to adopt a 20-week statute to promote maternal health by channeling women toward safer alternatives like childbirth or earlier abortion. Second, given the uncertainty of viability determinations, a state should be allowed to adopt a 20-week statute to protect viable fetuses from being aborted based on erroneous findings of nonviability. Third, the Supreme Court’s decision in Gonzales v. Carhart allows states to regulate based on new state interests not previously recognized. Interests supporting a 20-week statute — such as drawing a clearer line between abortion and infanticide and preventing fetal pain — should not be subject to the viability rule, which was developed to measure the state interest in protecting fetal life.

Fourth, if the Supreme Court finds these arguments unpersuasive, this article contends that principles of stare decisis would support reconsideration of the duration of abortion rights in a case involving a 20-week statute. A federal appellate court panel recently urged the Supreme Court to reconsider the viability line. Stare decisis principles support revisiting a rule applied in earlier cases where the justifications for the rule were “never explored or analyzed in detail.” The uncertainty of a viability determination makes it an unworkable line to regulate medical practice and it is doubtful that many women have relied on abortion rights lasting until viability, rather than a week or two earlier. Decisions in recent decades (including Gonzales) have weakened the doctrinal foundations of the viability rule and factual developments — such as improved information concerning the risks of late-term abortions — would support reconsideration of the rule in a case challenging a 20 week statute.