"The usual rule in federal cases is that an actual controversy must exist at stages of appellate or certiorari review, and not simply at the date the action is initiated. United States v. Munsingwear, Inc., 340 U. S. 36 (1950); Golden v. Zwickler, supra; SEC v. Medical Committee for Human Rights, 404 U. S. 403 (1972). But when, as here, pregnancy is a significant fact in the litigation, the normal 266-day human gestation period is so short that the pregnancy will come to term before the usual appellate process is complete. If that termination makes a case moot, pregnancy litigation seldom will survive much beyond the trial stage, and appellate review will be effectively denied. Our law should not be that rigid. Pregnancy often comes more than once to the same woman, and in the general population, if man is to survive, it will always be with us. Pregnancy provides a classic justification for a conclusion of non-mootness. It truly could be "capable of repetition, yet evading review." Southern Pacific Terminal Co. v. ICC, 219 U. S. 498, 515 (1911). See Moore v. Ogilvie, 394 U. S. 814, 816 (1969); Carroll v. Princess Anne, 393 U. S. 175, 178-179 (1968); United States v. W. T. Grant Co., 345 U. S. 629, 632-633 (1953). We, therefore, agree with the District Court that Jane Roe had standing to undertake this litigation, that she presented a justiciable controversy, and that the termination of her 1970 pregnancy has not rendered her case moot."