The Wall Street Journal has brought us the news that combining motherhood and careers is overtaxing professional women and some of them are dropping out of the work force. That working mothers are overtaxed is not going to surprise any female reader of the Journal. What is surprising, however, is the unenlightened way in which corporations have responded to the problems facing professional women who built careers in the 70s and are now, perish the thought, having babies.

A manager in a manufacturing concern, who had an MBA from Harvard, found she could no longer keep the hectic pace after her baby was born. She asked for part-time hours. The company refused and she quit. A public relations woman quit her firm after her baby's birth rather than return to a job that she knew required more than a 40-hour week. Another woman went back to work a month after her baby was born because her employer provided no maternity leave. She said she believes her work is suffering because of motherhood. Other women returned to work early and felt terrible because they missed their babies or missed meetings because of children's emergencies.

The Journal's findings reinforce other recent reports about the difficulties working mothers are having, no matter what their income level. But it adds another dimension to the picture: the high cost to corporations that lose experienced professional women because the male corporate environment has failed to respond to the biological pressures on their female employes.

In fact, a recent survey by Working Woman magazine revealed that deeply entrenched opposition to working mothers persists, despite their growing numbers and despite an understanding of the economic and social forces that have propelled them into the work force. Fifty-three percent of the men and 43 percent of the women surveyed said they believe that a woman who works should not have children, a rather staggering price to exact when you consider that more than half of American women work. Sixty-three percent of the men and 52 percent of the women surveyed thought it was bad for young children to have working mothers. Yet 90 percent of those surveyed agreed that most mothers work outside the home because they need the money and most supported improved day care.

A resounding indication of the difference in male and female awareness of the problems came in a question about granting employes days off to care for sick children: 90 percent of the working mothers and 85 percent of all women surveyed said yes, while only 65 percent of the men did.

Women are the fastest growing part of the labor market; 46 percent of America's children under the age of 6 have mothers who work. To say working women should not have children defines childbearing as the exclusive province of the very rich or of the unemployed, hardly socially desirable goals. Yet to make the task so difficult for working women will inevitably force them out of the labor force or out of childbearing or tax them to a point that they will do neither job well.

There are a variety of measures employers can take to ease the pressures on working mothers so that they can still continue their careers: part-time work with prorated benefits, four-day workweeks, options to work part of the time at home, job-sharing, flexible schedules and day-care assistance have all been found to help. It is a fairly safe bet that a professional woman who has risen through the ranks of a corporation for a decade or so before having a baby will be able to get more done in three or four days than someone new to the corporation would get done in five.

It is also incumbent on employers to adopt liberal maternity leave policies so that new mothers will not feel pressured to return before they have regained their strength, spent the time they want with a new baby and found reliable child care. Six months of understanding can yield a long-term employe instead of a resignation.

Following the passage of the Pregnancy Disability Act of 1978, which prohibited discrimination on the basis of pregnancy and childbirth, employers discovered that the American industrial machine was not brought to a halt by having pregnant women on the job and new mothers off the job. Having survived that first jolt, it would seem logical that the next fact of life to which employers must adapt is that once women start having children, they have a compelling desire to take care of them.