Members of two House panels are blocking a $900,000 grant from the Agency for International Development to a Louisiana group that promotes "natural" family planning overseas while refusing to supply information on other forms of contraception.

Members of the House Foreign Affairs Committee and the House Appropriations subcommittee on foreign operations have held up the grant to the Family of the Americas Foundation of Mandeville, La., because of their concern about a new AID policy that would give grants to groups that refuse to provide couples with information on a wide variety of contraceptive choices.

The foundation promotes "natural" family planning, in which couples must refrain from intercourse during the portion of a woman's menstrual cycle when she is fertile . The foundation, which says other forms of contraception destroy life in its earliest forms, had lobbied AID to change its policy.

In a separate development, it was learned that AID Administrator M. Peter McPherson had cabled William Wilson, U.S. ambassador to the Vatican, on July 31 to inform him that the policy had been changed. McPherson said in a telephone interview last week that informing the Vatican through Wilson was simply a "diplomatic courtesy." But Democratic members of Congress who monitor AID were not notified of the change until Aug. 9. On July 16, a week after AID formally changed its so-called "informed consent" policy, it sent Congress a request to redirect part of $7 million that Congress had obligated in fiscal 1985 for efforts to promote natural family planning overseas. The reprograming request would have extended a grant to the foundation to make a film, and provided an additional $900,000 to promote natural family planning in Africa, Asia and Latin America.

When Congress approved the $7 million program, grant recipients were required to supply information on a variety of contraceptives.

The foundation's executive director, Mercedes Wilson, did not return repeated phone calls requesting comment.

Despite the subcommittee's initial opposition, the foundation secured a $1.1 million grant earlier this year to make a film explaining the so-called Billings contraceptive method. The method requires women to test their cervical mucous to determine when they are fertile and thus should abstain from intercourse. At the time, some panel members, including Matthew F. McHugh (D-N.Y.) and Rep. William Lehman (D-Fla.), expressed concern about the group's opposition to other contraceptive methods. However, the grant went through after Rep. Robert L. Livingston (R-La.), a full committee member who used to serve on the subcommittee, intervened, according to William Schuerch, a subcommittee staff member, and other sources.

Livingston represents the area where the foundation is located.

In an Aug. 9 letter to Lehman, McPherson said the new policy was designed to permit all organizations that promote natural family planning to qualify for AID grants.

McPherson emphasized that AID's new policy did not mean that the agency planned to promote only natural family planning programs.