After considering the fundamental constitutional questions resolved by Roe [v. Wade, 410 U.S. 113 (1973)], principles of institutional integrity, and the rule of stare decisis, we are led to conclude this: the essential holding of Roe v. Wade should be retained and once again reaffirmed.

It must be stated at the outset and with clarity that Roe’s essential holding, the holding we reaffirm, has three parts. First is a recognition of the right of the woman to choose to have an abortion before viability and to obtain it without undue interference from the State. Before viability, the State’s interests are not strong enough to support a prohibition of abortion or the imposition of a substantial obstacle to the woman’s effective right to elect the procedure. Second is a confirmation of the State’s power to restrict abortions after fetal viability, if the law contains exceptions for pregnancies which endanger a woman’s life or health. And third is the principle that the State has legitimate interests from the outset of the pregnancy in protecting the health of the woman and the life of the fetus that may become a child. These principles do not contradict one another; and we adhere to each. . . .

III

A [W]hen this Court reexamines a prior holding, its judgment is customarily informed by a series of prudential and pragmatic considerations designed to test the consistency of overruling a prior decision with the ideal of the rule of law, and to gauge the respective costs of reaffirming and overruling a prior case. Thus, for example, we may ask whether the rule has proved to be intolerable simply in defying practical workability; whether the rule is subject to a kind of reliance that would lend a special hardship to the consequences of overruling and add inequity to the cost of repudiation; whether related principles of law have so far developed as to have left the old rule no more than a remnant of abandoned doctrine; or whether facts have so changed or come to be seen so differently, as to have robbed the old rule of significant application or justification, e.g., Burnet v. Coronado Oil Gas Co., 285 U.S. 393 (1932) (BRANDEIS, J., dissenting). . . .

Although Roe has engendered opposition, it has in no sense proven "unworkable," representing as it does a simple limitation beyond which a state law is unenforceable. . . .

We have seen how time has overtaken some of Roe’s factual assumptions: advances in maternal health care allow for abortions safe to the mother later in pregnancy than was true in 1973, and advances in neonatal care have advanced viability to a point somewhat earlier. But these facts go only to the scheme of time limits on the realization of competing interests, and the divergences from the factual premises of 1973 have no bearing on the validity of Roe’s central holding, that viability marks the earliest point at which the State’s interest in fetal life is constitutionally adequate to justify a legislative ban on nontherapeutic abortions. The soundness or unsoundness of that constitutional judgment in no sense turns on whether viability occurs at approximately 28 weeks, as was usual at the time of Roe, at 23 to 24 weeks, as it sometimes does today, or at some moment even slightly earlier in pregnancy, as it may if fetal respiratory capacity can somehow be enhanced in the future. Whenever it may occur, the attainment of viability may continue to serve as the critical fact, just as it has done since Roe was decided; which is to say that no change in Roe’s factual underpinning has left its central holding obsolete, and none supports an argument for overruling it.