The Supreme Court begins its 1990-91 term Monday with disputes looming over abortion counseling, fetal protection, school desegregation and the war on drugs.

There will also be a new face on the court this term - David H. Souter.Among the cases to be heard this week, without Souter, are an important desegregation battle from Oklahoma City and a big-money showdown over punitive-damage awards.

President Bush picked the conservative Souter, a federal judge from New Hampshire, as the 105th member of the high court, replacing its longtime liberal leader, Justice William J. Brennan.

"We see troubled times," said John Powell, chief lawyer of the American Civil Liberties Union, in assessing the coming term. "The court has shown a willingness to reconsider and cut back hard-won victories we thought were long over."

Souter, whose vote is seen as pivotal in abortion, affirmative action and church-state relations cases, could pad Chief Justice William H. Rehnquist's working conservative majority. Souter's nomination was endorsed Thursday by the Senate Judiciary Committee and sent to the full chamber for confirmation.

Abortion rights advocates who oppose his selection said Souter, if given the chance, would provide the critical fifth vote to overturn the court's 1973 Roe vs. Wade decision, which legalized abortion.

"His adamant refusal" in his Senate confirmation hearings "to be candid in the area of privacy and abortion can do nothing but create the very reasonable and strong inference that he is prepared to jettison established law," said Helen Neuborne of the National Organization for Women's Legal Defense and Education Fund.

Under Supreme Court practice, Souter would not be able to participate in cases argued before he joined the court. If the justices find themselves split 4-4 on such a case, they could order it reargued later in the nine-month term to let Souter cast the deciding vote.

The court already has agreed to decide 54 cases by July, when its term will end, and probably will add 70 to 80 more in the coming weeks.

The first cluster will be added Monday, when the justices are expected to issue orders in more than 1,000 appeals. The vast majority will be rejected but some will be granted review by the court.

In one of its most closely watched cases, the justices must decide whether federal regulations violate free-speech rights by barring government-financed family planning clinics from offering abortion counseling.

At stake is the future scope of a $200 million-a-year federal program that finances more than 4,000 clinics serving some 5 million low-income women.

The family planning program, enacted by Congress as Title X of the Public Health Service Act, forbids clinics from using federal funds to perform abortions, although it originally let clinic staffs tell women about the abortion option.

But the Reagan administration in 1988 issued regulations that say clinics receiving federal support may not "encourage, promote or advocate abortion as a method of family planning" or even distribute written materials on abortion.

If a woman visiting such a clinic asks about abortion, the regulations tell doctors and counselors to say the program "does not consider abortion an appropriate method of family planning" and to offer help in obtaining prenatal care.

The Senate last week voted to amend Title X to nullify the regulations against abortion counseling. If the Senate action becomes law, the court challenge of the regulations will become meaningless.

In a case that could affect millions of working women, the court is reviewing an employer's policy of excluding all women of childbearing age from some hazardous jobs.

A fetal-protection policy used by Johnson Controls, a Milwaukee-based battery manufacturer, bans women who cannot prove they are infertile from jobs that expose them to lead. The policy is being attacked as a form of illegal sex discrimination.

Among those who sued were a 50-year-old divorcee and a woman who submitted to sterilization to preserve her job.

A federal appeals court upheld the policy by a 7-4 vote, but one dissenting judge said 20 million industrial jobs may be closed to women because "many substances in addition to lead pose fetal risks."

The Oklahoma City desegregation case asks whether school districts may abandon mandatory busing and other court-ordered plans after achieving racial balance in student populations.

Hundreds of school districts, including those in most major cities, operate court-ordered desegregation plans. Only a few have persuaded courts to declare their once-segregated systems fully integrated.

Nevertheless, the potential impact of the court's ruling is great. Critics say letting students attend neighborhood schools will result in "resegregation."