The Food and Drug Administration's approval of the most effective contraceptive ever available in the United States will substantially increase the range of choice that women have in regulating childbirth and holds the promise of quieting some of the furor over abortion.

The hormonal implant, called Norplant, works for five years and is surgically inserted under the skin in a woman's arm by a doctor using a local anesthetic. It can be removed in a similar procedure, and fertility returns within two months. It was developed in Finland in 1975. C. Wayne Bardin, of the New York-based Population Council, said that after two years of testing there, "we realized we had the most effective hormonal contraceptive anyone had ever seen." By 1983 it was approved for marketing in Finland. With the FDA's approval Monday of its use in the United States, it is now registered in 17 countries.

It has a reported failure rate one-tenth to one-twentieth that of birth control pills, the most effective contraceptives to date, which have a failure rate of about 6 percent. A significant reason for birth control failure is improper or erratic use of the method. This problem is eliminated with Norplant.

It will be sold in the United States by Wyeth-Ayerst Laboratories of Philadelphia, which expects it to be available in February.

About half the patients receiving Norplant experience disruption in their menstrual cycles that can include no bleeding for up to a year, spotting, or heavier bleeding, according to Bardin. Women with certain specific health problems such as acute liver disease and breast cancer should not use it, he said. But, he said, women with high blood pressure and smokers who should not use the pills made from estrogen and progestin can use Norplant, which contains only progestin.

The implant has been tested in 44 countries, Bardin said. "One of the reasons this is popular in countries that are developing has to do with the supply. In some rural communities they can't keep the pharmacy stocked with pills. In some countries where there are traditional religions, women are not allowed to be examined by any kind of health care worker unless their husband is present." They do not have to disrobe to have Norplant inserted, which means the husband does not have to be present, he said. "I didn't know this until we did clinical studies in those countries and found out how popular {the implants} are. Often the religion opposes contraception, but women have decided it is essential to their family health."

He predicted that in the United States "one of the groups of women that will be particularly attracted to Norplant are those who have completed their families and older women who haven't gone through menopause." He said the birth control pills that have combined hormones have provided "wonderful treatment" for women who experience severe menstrual cramps. Norplant, he said, is effective for them as well.

He said the Population Council is working on an implant for men and hopes it will be ready for clinical trials next year.

He also also said that the Population Council and the World Health Organization willl do long-term studies of women using Norplant to determine its effect over many decades.

Eleanor Smeal, president of the Fund for the Feminist Majority, has pointed out that only one American company, Ortho Pharmaceuticals, is now doing any research on contraceptives, down from about 20 doing such work before 1980. Yesterday, she called the Norplant approval "very historically important. I think it will become widely used. It's going to reduce the number of unwanted pregnancies, which will reduce the abortion rate."

Estimated costs for the implant, including doctor fees, have been about $500, substantially less than the five-year cost of the birth control pill, which can cost up to $18 a month, plus twice yearly exams. Smeal expressed the hope that the price of Norplant would go down, especially for those who could get it from public health programs. "We're spending something like $20 billion a year on unwanted pregnancies. It will definitely help reduce social problems if is is generally available."

The danger of something like Norplant, of course, is that women who are seen as a source of social problems, such as drug users, could be forced to use it. That ethical debate is sure to get started the minute some benighted judge orders a woman to use it or go to jail. But for the moment, there should be considerable jubilation among women over the first significant breakthrough in contraception in the United States since 1960. It is a major development in the struggle for reproductive freedom -- and reproductive responsibility.