BUENOS AIRES - The Argentine Congress passed a new law on reproductive health that provides for free birth control methods and advice to women nationwide, and will help prevent teen pregnancy, back-alley abortions, cancer of the reproductive system and breasts, and the spread of sexually transmitted diseases.

The bill, which was approved late Wednesday by the Senate, was opposed by the Catholic Church and a group of senators, who held up the vote in the upper house for a year and a half.

The Chamber of Deputies originally passed the bill, with slight modifications, in April 2001.

Once the bill is signed into law, the state will have to earmark special funds for financing its implementation nationwide, which will entail the creation of the necessary medical, psychological and social services, as well as the provision of contraceptives to female patients.

Health professionals in this Southern Cone country of 37 million applauded the new law as a huge stride forward.

But women's groups expressed misgivings about gaps and vague language in the text, questioning the absence of a list of birth control methods to be made available, which they say will enable medical institutions to leave aside methods they deem ''abortive.''

Women's activists also complain that the law is not clear with respect to whether minors will be able to seek birth control advice in public hospitals and clinics without parental permission.

Although the provisions created by the law must be followed in public hospitals, users of the private or trade-union based health care systems will also have access to the free birth control services and methods provided by the state.

Up to now, women have had to pay, for example, for the insertion of an intrauterine device (IUD), the most expensive form of contraception.

''This law will permit the public hospital to follow women throughout their child-bearing years,'' said Dr. Jorge Charalambopoulos, a professor of gynecology at the University of
Buenos Aires Faculty of Medicine, and the head of the responsible reproduction division at the Sardá state maternity hospital in the capital.

According to Charalambopoulos, women drawn to the doctor's office or health clinic by the possibility of free access to birth control will be subject to more regular controls.

''It will be the start of a relationship with the health system that will last throughout their reproductive years, and even later,'' said Charalambopolos.

He added that this new ongoing link involving periodic visits will help prevent around 150 deaths a year of women who undergo dangerous, back-alley abortions. Although abortion is illegal in Argentina, an estimated 450,000 are practiced every year.

The doctor likened the reach of the new programme to that of a national vaccination scheme.

The closer ties between the health system and women will make it easier to prevent the spread of HIV/AIDS among women, and to babies born to mothers with AIDS, he pointed out.

He also noted that the new law will help draw adolescents into consultations on birth control, where they will also receive advice on how to avoid infection with HIV/AIDS and other sexually transmitted diseases.

It will also help prevent breast cancer and cancer of the reproductive system, while fomenting breast-feeding. In addition, regular prenatal health controls will include testing for HIV, in order to provide the treatment needed to prevent mother-child transmission of the disease.

Dr. Ester Polak, the president of the Argentine Society of Sterility and Fertility, said the law was ''a big step forward, because it will enormously reduce many risks to women's health,'' as well as infertility. ''We will have healthier women,'' she predicted.

In Polak's view, the new law fills a legal vacuum, because free contraception services were already made available by statutes in the capital and in a few provinces, but not in others. ''Now all of the women in our country will enjoy equal access to treatment and care,'' she said.

But a few differences will remain. For instance, some provinces currently make available sterilisation procedures like tubal ligations and vasectomies free of charge. But the new national law does not cover such methods, due to their ''irreversible'' nature.

And in the greater Buenos Aires, a city of 12 million, teenagers can consult a doctor about birth control without permission from their parents, which they may not be able to do in all provinces.

Argentina's political parties left the decision on how to vote on the bill up to their representatives. Senator Nancy Avelín, from the western province of San Juan, said she voted against the bill because the population needed to grow in order to give the country a stronger domestic market.

Others based their decisions on religious convictions. Dr. Diana Galimberti, president of the Association for Sexual and Reproductive Health, told IPS that the local Roman Catholic Church sent the Senate a letter stating that it would be ''pleased'' if the bill were not approved.

The Church based its staunch opposition to the bill on the argument that it encouraged abortion, the use of ''abortive'' birth control methods, and state meddling in the question of sex education among minors.

''The problem is that when there are no parents to educate kids in questions of sexuality, the state must play a tutelary role, especially when we're talking about under-age women, who are increasingly prone to teen pregnancy,'' lawmaker María Luisa Storani, who represents Buenos Aires, told IPS.

Of every 100 live births in Argentina, 15 are the result of pregnancies among teens or preteens, a proportion that has increased in the past few years as an effect of the dire economic crisis.

Doctors point out that a first teen pregnancy usually leads to another, and that many teenage mothers have three or four children by the time they reach the age of majority.

An analysis of the number of teen pregnancies by district shows that the proportion is higher in areas where no free birth control programmes exist.

In 18 of Argentina's 24 provinces, the average number of births to teenage mothers is higher than the national average, while in the capital, which already has a statute on reproductive health, the proportion is only half the national average.