The case concerned an Arizona law, enacted in 2012, that prohibits abortions, except in medical emergencies, when the gestational age of the fetus is more than 20 weeks. The law’s definition of medical emergency is narrow, encompassing conditions requiring immediate abortion to avert a pregnant woman’s death or a “serious risk of substantial and irreversible impairment of a major bodily function.” The law’s sponsors claimed that fetuses can feel pain at 20 weeks, a contention that has been disputed by major medical groups.

Reproductive rights advocates won a small victory Monday. Without explanation, which is its standard approach, the U.S. Supreme Court turned down Arizona's effort to reinstate a law that prohibited most abortions 20 weeks after a woman's last menstrual period:A panel of three judges on the Ninth Circuit Court of Appeals had ruled eight months ago that the law was unconstitutional.

Arizona Gov. Jan Brewer, who pushed for the law in 2012, seems a bit confused about constitutionality. She claimed through spokesman Andrew Wilder that the Court's decision not to take up the case "is wrong, and is a clear infringement on the authority of states to implement critical life-affirming laws."

In fact, "viability" of the fetus outside the womb has long been the Supreme Court's standard, and the Ninth Circuit ruled Arizona "may not deprive a woman of the choice to terminate her pregnancy at any point prior to viability," and labeled the law "unconstitutional under an unbroken stream of Supreme Court authority, beginning with Roe and ending with Gonzalez [v. Carhart]." In March, the Ninth Circuit also struck down Idaho's 20-week ban on abortions. Eight other states still have such laws on the books, all of them held up in the courts.

Please read more about the Court's decision below the fold: