Opinion of the Court
at 63–64. If viability was not an essential part of the rule adopted in Roe, the Court would have had no need to make that comparison.
The holding in Colautti v. Franklin, 439 U. S. 379, is even more instructive. In that case, the Court noted that prior cases had “stressed viability” and reiterated that “[v]iability is the critical point” under Roe. 439 U. S., at 388–389. It then struck down Pennsylvania’s definition of viability, id., at 389–394, and it is hard to see how the Court could have done that if Roe’s discussion of viability was not part of its holding.
When the Court reconsidered Roe in Casey, it left no doubt about the importance of the viability rule. It described the rule as Roe’s “central holding,” 505 U. S., at 860, and repeatedly stated that the right it reaffirmed was “the right of the woman to choose to have an abortion before viability.” Id., at 846 (emphasis added). See id., at 871 (“The woman’s right to terminate her pregnancy before viability is the most central principle of Roe v. Wade. It is a rule of law and a component of liberty we cannot renounce” (emphasis added)); id., at 872 (A “woman has a right to choose to terminate or continue her pregnancy before viability” (emphasis added)); id., at 879 (“[A] State may not prohibit any woman from making the ultimate decision to terminate her pregnancy before viability” (emphasis added)).
Our subsequent cases have continued to recognize the centrality of the viability rule. See Whole Women’s Health, 579 U. S., at 589–590 (“[A] provision of law is constitutionally invalid, if the ‘purpose or effect’ of the provision ‘is to place a substantial obstacle in the path of a woman seeking an abortion before the fetus attains viability’ ” (emphasis deleted and added)); id., at 627 (“[W]e now use ‘viability’ as the relevant point at which a State may begin limiting women’s access to abortion for reasons unrelated to maternal health” (emphasis added)).
