Women who work have no more heart disease, on the average, than women who stay home, despite the often-voiced fear that as women work more, they will be unhealthier and lead shorter lives.

Though 42 percent of the work force is now female, there is on the whole no evidence yet that women have been losing their survival advantage over men.

Some working women, however, do suffer more heart disease than nonworkers. These are mainly clerical workers -- secretaries, typists, bookkeepers, cashiers, sales clerks -- who also have children to care for at home. The incidence of heart disease may be even higher for such women if they have bluecollar husbands.

Those conclusions were stated yesterday after one of the most searching studies so far of women and work. The study was conducted in Framingham, Mass.; as part of the federal government's "Framingham study," which has given medical science much of its best information on life styles and heart disease.

Why the higher heart attack rate among women clerical workers with children?

These women, said Dr. Suzanne Haynes of the National Heart, Lung and Blood Institute, are most often stuck in low-paying jobs where they feel lack of control, under-use of their skills and lack of recognition. And they must suppress their hostility toward unsympathetic bosses who give them little chance to vent their anger.

Child-caring, and possibly having a blue-collar husband who may not earn much either, may add to their burden.

Just the same, Haynes said in the current issue of the American Journal of Public Health, the assumptions that women, on the whole, will live fewer years if they work is unsubstantiated.

"On the contrary," she said, "in the last 10 years mortality rates from coronary heart disease have been declining in both men and women at all ages," and there have been even greater percentage declines among women than among men.

The average American woman lives to age 77.1, by 1977 figures; the average man 7.8 years less, to 69.3.

Haynes examined the medical histories of 387 working women, 350 housewives and 580 men. All were aged 45 to 64 in 1965-67. All were followed for eight years.

Whether they worked outside the home or not, women did report "significantly more" emotional tension than men.

But women and men workers were more likely than housewives to report emotional stress and marital problems. And working women reported more such stress and problems, as well as worries about aging, than working men. Most authorities believe that the final figures are far from in on the total effect of work on the lives of American women. Some reports have begun to show there may be more alcoholism, and also more car crashes, among working women.

But in the matter of heart disease, the number one killer ailment:

The women who had worked the longest, on the average -- the single working women -- had the lowest disease rate of all women. Just 4.2 percent of them suffered from a heart ailment, compared with 7.8 percent of all working women (defined as those who had worked outside the home for at least half their years since age 18), 8.1 percent of married working women and 8.5 percent of widowed, divorced or separated women workers. The rate for men was 12.8 percent.

The heart trouble incidence rose with the number of children among the women workers. Those with three or more children were twice as likely to develop heart disease as those with no children.

Twenty-one percent of the women clerical or sales workers who had children and blue-collar husbands developed heart ailments -- four times more often than housewives, nearly three times more often than working women in general and nearly twice as often as men.

But the clerical workers without children -- single or married -- were at no greater risk of heart disease then other workers.

Evidently, said Haynes, the extra burden of child care made the difference for the mothers employed in clerical work. And these women may also have been affected by the economic pressures, as a result of family size, that made them go to work in the first place.