Pregnant women who drink should be warned by a label on whiskey or wine bottles that alcohol can cause serious birth defects in their babies, Food and Drug Administration chief Donald Kennedy said yesterday.

The FDA is also getting ready to require drug makers to put warnings of possible ill effects on the package of a number of prescription drugs, probably starting with tranquilizers, he said.

And the agency is exploring ways to bring food advertising, including TV commercials, under regulations intended to protect children and others against nutritional "misinformation," he said.

The FDA currently is clearly empowered only to make the change in drug labeling. The other changes would probably require the cooperation of other federal agencies. Kennedy said. However, it seemed clear that action in all three of these areas would mean a wide extension of the way the federal government tries to protect the public.

But Kennedy argued some such actions are needed as the best way to control the nation's runaway medical costs by preventing disease.

The FDA commissioner - until early this year professor of human biology at Stanford University - made the statements at the annual meeting of the Institute of Medicine of the National Academy of Sciences. The institute is a group of 340 leading doctors and other health specialists who study the country's health problems and often advise federal agencies.

On alcohol and pregnancy. Kennedy said the FDA may lack authority to order new whiskey labeling, because of an Office of Management and Budget ruling that this power lies with the Treasury Department.

But "we ought to try" to get the authority and "we may soon ask the Treasury Department" to order a warning label because "the evidence is clear" that alcohol can harm fetuses, he said.

The FDA and National Institute on Alcohol Abuse warned women and doctors Abuse warned women and doctors in June that women who take anything more than two drinks a day may have children "with one or more" of a long list of defects, including malformed hearts, mouths, limbs or fingers, small heads and eyes and abnormal genitals. Doctors often define a "drink" as an ounce and a half of whiskey or a bottle of beer or a 4-ounce glass of wine.

On food ads, Kennedy said "there's really a lot of information and misinformation being dispensed," and "we've got to look at it as a part of people's education" that intimately affects their health. He called food ads "an extension of labeling" which should be "brought under the same regulations" as labeling.

But he said the agency would have to see what kind of authority it would need, and whether there would have to be new legislation before it can move far. He said he has been consulting with the Federal Trade Commission on possible approaches.

FDA officials have previously said they think many foods should carry "nutritional labeling" revealing nutritional content (proteins, carbohydrates, calories, and so forth). But the FDA lacks legal authority to require such labeling unless the product carries a nutritional claim.

Kennedy said the advertising he was concerned with was the kind cited in recent congressional testimony by Robert Choate. Washington's nutritional crusader. Choate described breakfast cereal ads in particular, but also candy, gum, cookie and cracker ads as those which arouse children's appetites for products which fail to give them adequate energy or nutrition.

As to drug package "inserts" or brochures for patients - so patients can be better informed about drugs potential ill effects - Kennedy asid "we are now selecting additional targets" beyond the few for which FDA now requires such information. These include birth control pills. IUDs (intrautcripe contraceptive devices) and, as of an order that has not yet taken effect, estrogens for use during menopause.

Kennedy replied that "we believe doctor-patient relations will be improved" if patients know more about drugs. He said oral diabetes drugs, some antibiotics and tranquilizers are possible subjects for such regulation, with tranquilizers a leading one because they represent 7 per cent of all prescriptions.

People often need such drugs, Kennedy said, but pointed out that many kinds of tranquilizers cause ill effects. Such ill effects can range from drowsiness to tremors to death when taken with alcohol.