The antiabortion bill that the Senate is now considering -- and which President Reagan suddenly has started pushing -- is a splendid illustration of how the right wing uses abortion as an organizing issue yet misses the point on ways to reduce abortions.

While permanently banning the use of federal funds for most abortions, the Helms "Human Life" bill asserts that the Supreme Court erred in its 1973 decision legalizing abortion, and declares that life begins at the moment of conception. Thank you and good night, Ayatollah Helms.

Abortions didn't suddenly come into being with the 1973 Supreme Court decision, and most even now are not paid for with federal funds. There were 600,000 legal abortions in 1972, when women could get them for reasons of mental and physical wellbeing. There were between 1.2 million and 1.3 million legal abortions in 1981. Where was the outraged right-wing in 1972?

Abortion is a private matter that ought to be left between a woman and her physician. It is not the president's business and it is not the business of the overwhelmingly male Congress to legislate guilt trips onto American women.

Having said that, it is important to note that Americans are ambivalent about abortion, and if Congress and the president were genuinely concerned about reducing the widespread use of it -- instead of playing politics with it -- they would probably find a good deal of support. According to the Gallup polls, only 25 per cent of the public supports legalized abortion under all circumstances; 53 per cent believe it should be legal only under certain circumstances. A Yankelovich survey found that while 70 percent of the women support abortion on demand, 56 percent of them believe abortion to be morally wrong. But surveys have found little support for the legislative sledgehammers Congress has been considering.

Its approach has been wrong. The same Congress and the same administration that are so concerned about abortion allocated the grand sum of $16 million in 1981 for federal research on contraceptive development. It spent a paltry $7.3 million for evaluation of the safety and efficacy of contraceptives. It spent $79.1 million on research into the reproductive processes. The total federal support for population research in 1981 was $151.4 million. That is roughly $50 million less than the cost of one B-1 bomber.

Money is just part of the problem, says Dr. Gabriel Bialy, head of research for the Center for Population Research. "Rather than investing our resources into fighting changes in abortion laws, maybe it's incumbent on our part to do a better job of selling the contraceptive methods now available.

"One could liken abortion to chemotherapy: necessary but drastic. Currently what people working in the cancer area are focusing on is not just the development of drugs that will inhibit tumor growth but they are looking at those factors that may contribute to the growth of cancer."

A similar approach ought to be used to reduce the need for abortions. Money ought to be spent on the development of improved contraceptives and Americans ought to be better educated on contraceptive use. The average failure rate for the condom and the diaphragm is 10 to 12 percent, Bialy says, but it was brought down to two percent in a program for underprivileged teen-agers when clinic employees took the time to carefully instruct them.

Bialy also believes there is a need for fundamental changes in Americans' attitudes toward contraceptives. "People are dissatisfied with what's available and when they are dissatisfied they use that as a rationalization for not using it. You talk to men and they give you a litany of reasons why they don't use the condom. In other elements of our lives we recognize we cannot have exacty what we want . . . That should be no excuse for not using what's currently available."

One-third of all abortions are performed on teen-agers. "If you can get the kids to think about the fact that fast foods don't provide them with good nutrition," he says, "isn't it possible that we could succeed in getting the idea across that junk sex is just as bad for them?"

Congress has spent far too much time debating such questions as when human life begins. No one, with the exception of Jesse Helms, knows the answer to that. But we do have some understanding of when the need for abortion begins: it begins with ignorance, with contraceptive failure, with poor attitudes about reproduction. We have found that public education has changed attitudes about smoking. It can also change attitudes about sex.