A new birth control product for women, the contraceptive sponge, may be approved by the Food and Drug Administration soon, perhaps in the next few weeks, officials say. An FDA advisory committee has already recommended approval.

The soft polyurethane sponge, which contains a spermicide, would be sold over-the-counter in drug stores under the name "Today" by VLI Corp. of Costa Mesa, Calif. It is the "only vaginal birth control product that allows for sexual spontaneity," company representative Debra Gaynor said. This could mean a distinct advantage over contraceptives like foams and gels, which must be inserted shortly before intercourse. Related story on Page A9

The sponge "could be inserted up to 24 hours before intercourse and you can have intercourse as much as you want without doing anything else," she said.

The company says that the sponge has been under development for seven years and that clinical tests, sponsored by the National Institutes of Health, have shown it about 90 percent effective, "essentially as effective as the diaphragm," Gaynor said.

If approved, the disposable sponges would sell for about $1 each and be available later this year.

DES STILL FATTENING CALVES: The FDA went to court last week charging that four New York farms were using the banned cancer-causing chemical diethylstilbestrol (DES) to fatten more than 1,000 calves for fancy veal. The suspect hormone was banned as an animal additive in 1979, after new testing techniques found residues in meat.

Illegal use by beef producers was found in 1980, but this is the first such case with veal. Three of the four farms agreed this week to voluntary injunctions against further DES use, FDA spokesman William Grigg said. They will pay the agency to test the calves and will sell them only for non-food use if any DES is found.

But the FDA is pursuing court action against the operators of the fourth farm, Tomahara Farms of New Hartford, N.Y., Grigg said. The actions follow a nine-month investigation by the FDA's Buffalo district office.

The FDA said it does not know of any contaminated veal currently on the market, but the Agriculture Department has confirmed DES in the tissue of 93 carcasses, now in storage in New York, from one of the farms.

DRUG ADS TO THE PEOPLE: Traditionally, prescription drug products have been sold to doctors through extensive ads in medical journals and visits from drug company representatives. Now many drug companies are considering whether to take their case directly to the consumer, putting new pressure on physicians.

The idea has prompted concern from consumer groups as well as the American Medical Association. The issue will be the topic of the next consumer exchange meeting between FDA Commissioner Arthur Hull Hayes Jr. and the public. It is set for 10 a.m. Monday, March 28, in the Health and Human Services North Building auditorium, 330 Independence Ave. SW.

Dr. Lloyd Millstein, FDA's acting director of drug advertising and labeling, said yesterday that companies already can advertise to the public, but fall under government regulations requiring balanced presentation of "good new and bad news" about the drug. He said companies have been seeking guidance about how to proceed with mass media presentations.

Dr. Sidney Wolfe, of the Nader-founded Health Research Group, warned that "misleading" mass promotion contributed to the quick popularity of the anti-arthritis drug Oraflex, which was voluntarily removed from the market last year, three months after it was approved, in response to reports of deadly side effects.