Those who would outlaw abortion have received a sharp and perhaps unexpected blow from the United States Supreme Court. The high tribunal's detailed ruling in a trio of cases handed down Wednesday says, in essence, that states may not regulate a woman's freedom to have an abortion during her second three months of pregnancy. In so doing, the court appeared to be choosing individual rights over government's right to regulate.
Civil rights advocates, including women's groups, generally hailed this decision as a victory. On the other hand, right-to-life organizations seemed stunned. And it is clear that the Reagan administration will have to reassess its clear anti-abortion stance, which includes support for a constitutional amendment banning abortion.
The ruling ''is a signal to politicians in the US to keep their hands off,'' insists Julie Steiner of the American Civil Liberties Union. Janet Benshoss, director of the Reproductive Freedom Project, sees it as a stand ''for women and privacy rights.''
Ms. Benshoss is particularly elated by the court's finding in an Akron, Ohio, case. She says it should effectively put an end to ''harassing statutes'' statutes in over 20 states that up to now have limited a woman's freedom to have an abortion.
Legal analysts say the ruling regarding Akron is the most significant of the three. (The others apply to abortion laws in Virginia and Missouri.) It clarifies a landmark l973 decision, Roe v. Wade, which legalized abortion but left with individual states the option of regulating access to abortions during the second trimester if such regulation would protect a woman's health.
All three cases involved mandatory hospitalization for second trimester abortion.
The court voted 6 to 3 in the Akron case. Justice Lewis Powell, writing for the majority, said the city ''has imposed a heavy, and unnecessary, burden on women's access to a relatively inexpensive, otherwise accessible, and safe abortion procedure.
''Present medical knowledge convincingly undercuts Akron's justification for requiring that all second trimester abortions be performed in a hospital,'' he added.
The court also struck down a highly controversial provision of the l978 Akron ordinance - the so-called informed consent provision. This required a physician to give a woman seeking abortion a vivid anatomical description of the fetus and make a value judgment regarding the starting point of human life. The court called this a ''parade of horribles,'' and said it intruded on a woman's privacy rights.
In a related ruling on a Virginia law, the court said although states cannot require that abortions be performed in full-service hospitals, they may demand that they take place in licensed out-patient clinics.
If there was any solace for those who firmly oppose abortion or favor strict public control of it, it came in the Missouri case. The Supreme Court voted by a narrow 5-to-4 margin to uphold a portion of that state's l979 abortion regulation package. The regulatory plan had been struck down earlier by the St. Louis Court of Appeals.
Justice Powell said that states may require that consent be obtained from parents or a juvenile court before an abortion can be performed on a minor. The court also upheld, in the Missouri case, a requirement that a second physician be present during an abortion as ''reasonable exercises of a state's concern'' for a mother's health.
In total, these rulings can be seen as a strong rebuff to the New Right groups which have lobbied for anti-abortion legislation as well as for a constitutional amendment banning abortion. The ''court stripping'' attempts by Sen. Orrin Hatch (R) of Utah and other conservatives - which included proposed legislation to limit court jurisdiction in abortion matters - failed to gain ground in Congress last year. These bills have been bottled up in committee again this year.
Justice Sandra Day O'Connor, President Reagan's only Supreme Court appointee and the court's first and only woman, voted against the majority to uphold the rights of states to regulate access to abortion.