The Food and Drug Administration yesterday proposed that pregnant and nursing women be warned not to use common over-the-counter drugs without first seeking professional advice.

The sweeping warning label under consideration would be required on bottles and boxes of all non-prescription drugs that are absorbed by the body, including aspirin, cough and cold products and sleep aids, FDA officials said. It would not be needed for medicines that are rubbed on the body, such as ointments and lotions.

From 37,000 to 62,000 different products may be affected, according to William Gilbertson, who heads FDA's division of over-the-counter drug evaluation.

The warning proposed by the FDA would state: "As with any drug, if you are pregnant or nursing a baby, seek professional advice before using this product." The professional advice could be obtained from the woman's physician or pharmacist, as well as nurses, nurse-practitioners, and midwives.

While this new regulatory initiative may appear to conflict with the Reagan administration's anti-regulatory push, it is not expected to be controversial.

Many doctors and consumer groups long have suggested that the most prudent advice for a pregnant woman, particularly in the first three months of pregnancy, when there is an increased risk of birth defects, is to avoid medication if possible.

While over-the-counter drug manufacturers are not eager for such a warning, they are more concerned about differing state laws already in the works requiring that pregnant women be warned about taking non-prescription products without their doctors' advice.

California, for example, has a law that is scheduled to go into effect in November. Gilbertson said that the FDA had been discussing the need for warning labels with California for a number of years and the state finally went ahead on its own.

He said that the government believed the FDA regulation would preempt state actions.

FDA spokesman Faye Peterson added that the national requirement would eliminate "confusion for consumers" that would result if there were a patchwork of different state requirements.

James D. Cope, president of the Proprietary Association, said yesterday that his industry trade group representing the manufacturers and distributors of over-the-counter drugs is behind the FDA "110 percent" in its effort to establish a national labeling approach.

"We applaud the FDA for taking this first step toward regulatory uniformity in over-the-counter drug regulation. It is much needed. Industry simply cannot comply with differing rules imposed by 50 'mini-FDA.' "

But the industry group argued that it continued to believe that such a "blanket warning" is "unwise," but if one is required, the FDA should do it.

The government's estimate of the first-year cost to drug companies of changing the labels was between $3.8 million and $5.7 million.

Now, only a small number of drugs carry specific warnings about the dangers of taking the medication during pregnancy. Where such labels do exist, they would remain on the product. Peterson said that several sleep-aids and cough syrups already contain warnings because of an antihistamine that carries a risk of birth defects.

The FDA is also considering a recommendation from an outside advisory group that pregnant be women be warned about the use of aspirin in the last three months of pregnancy because of possible bleeding problems.

In most cases, however, there has not been sufficient testing to demonstrate that a drug is safe for unborn or nursing children.

"Even where there are no data to suggest that particular over the counter drugs present a potential hazard, there also may be no data demonstrating that such drugs are safe when used by pregnant or nursing women," noted an FDA statement.

"It makes good sense to advise mothers-to-be and new mothers that they should not use any drug unless it is medically necessary," said Health and Human Services Secretary Richard S. Schweiker.

Despite growing concern in recent years about the problem, some studies have suggested that the use of drugs by pregnant women has increased rather than decreased. A University of Florida study found that one group of women each took an average of 11 prescription and non-prescription products.

Dr. Ervin Nichols of the American College of Obstetricians and Gynecologists, which represents physicians, voiced support yesterday of the government effort to place warning labels: "We think its a realistic approach."

Dr. Sidney Wolfe, of the Ralph Nader-backed Health Research Group, questioned why it had taken so long for the government to act.

The proposal, to be published in the Federal Register next Tuesday, will have a 30-day comment period. Once made final, it will give manufacturers a year to meet the new labeling requirements.