FDA Plans to Bolster Aspirin Label Warning : Health: Women will be urged against use during the last three months of pregnancy. The intent is to avoid harm to the fetus or delivery complications.

The Food and Drug Administration soon will require labels on all over-the-counter aspirin products warning pregnant women not to take such drugs in the final trimester without a physician’s specific order, according to acting FDA Commissioner James S. Benson.

The regulatory agency hopes to impose the warning, designed to avoid harming a fetus or delivery complications, “in the next several months,” Benson said.

His surprise announcement came in a March 29 letter to California health officials in Sacramento, where a copy was made available to The Times.

Currently, aspirin products carry only a general warning used on all orally taken, over-the-counter drugs. That warning, required since 1982, advises pregnant women not to ingest such medications without a physician’s approval.

The proposed language of the impending warning is:

“It is especially important not to use aspirin during the last 3 months of pregnancy unless specifically directed to do so by your doctor because it may cause problems in the unborn child or complications during delivery.”

The wording is identical to that now required for several other classes of over-the-counter painkillers, known as ibuprofen products.

“There is a concern, though not a hell of a lot of data,” about aspirin’s possible harmful effects during the final trimester, one FDA official said Wednesday night.

For more than a decade, the FDA has been considering a warning requirement for aspirin.

Benson’s letter to Thomas E. Warriner, undersecretary of the California Health and Welfare Agency, came just as state officials in Sacramento were preparing to require precisely such a warning for over-the-counter aspirin products.

Gov. George Deukmejian’s panel of scientific advisers is expected to take such action on Friday, under the authority of Proposition 65, the anti-toxics law approved by California voters in 1986.

According to Benson, aspirin manufacturers would be given a year to begin labeling their products with the new warning.

Aspirin industry leaders, who were en route to California for Friday’s Proposition 65 meeting, could not be reached for comment.

Aspirin has been studied extensively for its intended and unintended health effects. But the results have been mixed and often contradictory.

Most recently, a study published in the authoritative New England Journal of Medicine reported last August that low doses of aspirin in late pregnancy can prevent a potentially fatal form of high blood pressure among pregnant women.

The study’s authors noted that their tests involved the ingestion of only 60 to 100 milligrams--far less than the usual adult dose.

Another recent study found that regular doses of aspirin can cut in half a person’s risk of stroke from an irregular heartbeat.

Still another concluded that an aspirin every other day can cut the risk of heart attack in half for men over age 50 and confer even greater benefits to those at the highest risk of heart attacks because of smoking, high cholesterol levels or diabetes.

Chen reported from Washington and Paddock from Sacramento.