Don't call it rhythm.

That's one six-letter word Barbara and Mike Taylor of Falls Church -- and 1,800 other Northern Virginians -- just don't like.

They are members of nationwide organization called the Couple to Couple League. What they espouse is a method of natural birth control called "fertility awareness" or the "sympto-thermal" system. Proponents say couples trained in the method can tell with nearly absolute certainty when a woman is fertile, thus preventing pregnancy as well as aiding women who have been unable to conceive.

But most important, say league members, the method is safe.

"People are very hungry for it," says Barbara Taylor. "They want to learn how not to be slaves to drugs, devices and operations."

A growing number of people -- 60,000 in 45 states at last count -- are learning the method in classes taught by the league. Many couples take advanced courses so they can also teach the method -- hence the name, Couple to Couple.

League members, who are almost evangelical in their determination to inform the public about the method, claim it appeals to all kinds of people: back-to-nature types who abhor the use of drugs, feminists who reject methods which can endanger a woman's health and deeply religious people who believe artificial contraception is wrong.

The Taylors, who teach the method and have practiced natural birth control since they were married four years ago, are still (deliberately) childless and contend that the method is highly effective.

A pamphlet published this year by the former U.S. Department of Health, Education and Welfare supports the league's contention that fertility awareness is about 99 percent effective when used properly. By contrast, the traditional "rhythm method" gets a 65 to 80 percent effectiveness rating in several other studies.

The rhythm method is based on mathematics, primarily by calculating fertile periods based on six consecutive menstrual cycles. For women with irregular menstrual cycles, the method makes it difficult to accurately preidct fertile periods. By contrast, say league members, fertility awareness is "a way of life," a constant monitoring of the body which enables women to detect when ovulation is about to occur.

One problem facing the league which was founded in 1971, is how to get the word out about their method.

"We're basicaly a word of mouth organization," says Mike Taylor.

For the most part, league members say, doctors do not present fertility awareness as a birth control device because they are unfamiliar with how it works or they do not have the time to instruct patients.

The league has a list of area physicians who endorse the method, and most send their patients to league classes.

Dr. William Colliton, a Silver Spring gynecologist-obstetrician, has prescribed fertility awareness and other conventional methods of birth control for the past decade, but decided six months ago to exclusively prescribe the natural method.

"Women want to know how to not get pregnant without destroying their bodies," Colliton says bluntly.

The Couple to Couple League course includes four classes, lasting two hours each and spaced four months apart. Students are encouraged to begin using a conservative version of the method after the first class.

The following classes are being offered at Alexandria Hospital. Interested persons should call the numbers listed:

July 12 -- call 750-1792; August 2 -- call 578-1389; September 20 -- call 578-1389. A class also has been set for the Dale City area beginning July 28; call 339-6738. CAPTION:

Picture, Mike and Barbara Taylor, of the Couple to Couple League: "People want to learn how not to be slaves to drugs, devices and operations." By Sharon Farmer for The Washington Post