House conferees yesterday rejected a proposed Senate compromise on federal funding of abortions, contending it would allow too many women to obtain free abortions under the Medicaid program.

But they drafted a counterproposal for presentation to the Senate conferees next week. It would allow federal payments for abortions to save the life of the woman and also federal funding of "prompt treatment" for rape and incest. "Treatment," in the House proposal, doesn't mean an abortion performed months after the fact of pregnancy is established, but simply a dilation and curettage or administration of anti-implantation drugs within a few days or weeks, at most, after the rape or incest occurs.

House conferees worked up their counterpronosal after rejecting a more permissive compromise submitted by Sen. Warren G. Magnuson (D-Wash.) Thursday, with only Louis Stokes (D-Ohio) and Edward R. Roybal (D-Calif.) voting for the Magnuson approach.

Magnuson predicted yesterday that the Senate conferees would turn down the House counterproposal as too restrictive.

The language originally proposed by the House for inclusion in the ficsal 1978 money bill for the Departments of Labor, and Health, Education and Weliare was identical to language voted last year - banning Medicaid funding of abortions for poor women unless needed to save the life of the woman. Last year's language, included in last year's appropriation bill, expired last night when the fiscal year ended. The House wants to continue it for another year. In past years, HEW had been funding about 250,000 to 275,000 abortions annually, a fourth of the estimated national total.

The Senate, in its initial version of the bill, voted a much weaker abortion provision, permitting federal funding not only to save the woman's life, but also in cases of rape and incest and wheneven a doctor, for whatever reason, considered it "medically necessary." House members said "medically necessary" was so broad it would allow abortion for almost any physical or psychological reason.

After months of haggling, Magnuson Thursday came up with a compromise: allow abortions to save the life of the woman, in cases of rape or incest, or "if the woman or fetus would suffer serious, permancent health damage" from continuation of the pregnancy.

This was the language rejected by the House conferees yesterday as too permissive.