Religious opposition to population control in practice mainly takes the form of opposition to family planning and artificial contraceptive methods based on interpretations of scriptures and religious teachings.
Its effect tends to encourage elitism in development since statistics show that even where religious taboos on contraception exist, it is nevertheless widely practised in developed countries and among the rich in developing countries, and birth rates are on a par with those of societies where there is no religious taboo. Those who follow religious doctrine on this point are mainly the poor and uneducated. Religious opposition to population control may be encouraged or discouraged by government policy depending on control and depending on how strong the religious influence is in politics. Religious opposition may already be built into the law, not only regarding birth control but also into family and marriage law, age of majority, education, status of women and other laws which affect the use of birth control.
Vatican diplomacy has been remarkably successful in blocking any official international endorsement of "unnatural" methods of birth control especially in the form of family planning programmes. The Pope's recent concern has been over the secularization of Poland where, in 1991, at least at least 81% of Poles did not believe the Catholic Church had the right to demand submission to its contraception policies, and 71% rejected its authority on the matter of abortion. In 1992, the Vatican was instrumental in ensuring that population control and family planning were removed from the agenda of the UN Conference on Environment and Development (Rio de Janeiro). At the 1994 Cairo Population Conference the Papal delegation kept the abortion issue at the centre of the negotiations; however at the end only it and a few Catholic countries from Latin America maintained objection. The diplomatic initiatives of the Vatican have been assisted by the World Muslim League which is apparently concerned at unacceptable changes to the role of women in Muslim societies brought about by family planning and the implications of a woman's freedom of choice in a male-dominated society.
The Catholic Church has one of the best-run lobbies in the USA. Its opposition to U.S. funding of international family planning has been palpable. Thus in 1984, in deference to the Vatican position, the Reagan administration announced at the World Conference on Population (Mexico City), that the USA was withdrawing funding from the world's two largest family planning organizations: the United Nations Fund for Population Activities and the International Planned Parenthood Federation. In 1995, the pope issued an encyclical threatening to remove Church sponsorship of those Catholic healthcare organizations that failed to strictly obey church doctrine on matters like sterilizations and contraception. In the USA, there has been the outright elimination of reproductive health services when Catholic hospitals join or take over non-Catholic institutions. The Catholic organizations are forming networks, extending their influence and fortifying their leverage for future negotiations. Fifteen percent of the nation's nonfederal hospital beds are now in the hands of close to 600 Catholic hospitals. Often, the only hospital in a community is Catholic-run.