AFTER LAST YEAR'S tedious congressional battle over abortion funding, we doubt that many members of Congress relish the prospect of another such struggle this year. But the arguments will be starting up again when the Health, Education and Welfare appropriations bill comes to the House floor this week. The House Appropriations Committee has attached a rider that would bar federal funding of abortions (primarily through Medicaid) "except where the life of the mother would be endangered if the fetus were carried to term."

Our objections to this rider only start with the fact that it is far more restrictive than the compromise finally arrived at last December. That provision, which expires on Sept. 30, also permits federal payments for abortions in cases of rape and incest (when the assault has been properly reported), or when two physicians determine that "severe and long-lasting physical health damage to the mother would result" from continuing the pregnancy.

The current formulation is also deficient, in our view. It bars federal aid in other situations of great distress - for instance, where a fetus is deformed or bears an incurable genetic disease, or where a pregnancy is causing acute mental anguish for the women or girl involved. And such omissions point to one basic defect in any categorical approach. No matter how many exceptions and qualifications Congress may compose, general restrictions are bound to deal arbitrarily with cases involving medical and emotional judgments of the most personal, agonizing kind.

There is another fundamental inequity here. Congress is not only imposing its own judgement of the worthiness or acceptability of abortions in various circumstances. It is also imposing that judgment on only one class of citizens: those who happen to be poor. Supreme Court decisions have established that all women have a clear constitutional right to terminate a pregnancy by abortion, if they choose to, at least through the first three months. Denying federal aid effectively limits the exercise of that choice to women who can afford private medical care - or who live in jurisdictions that have decided to provide aid. We think such federal discrimination is wrong and that Congress should refrain from legislating these curbs and allow individuals to make the decisions freely for themselves.