The Reagan administration is demanding "more sacrifice from children than from any other group in American society" with its proposed cuts in welfare, education, nutrition and other programs, the head of the Washington-based Children's Defense Fund charged yesterday.

President Marian Wright Edelman said an analysis of the administration's budget proposals indicates that more than 750,000 pregnant women would become ineligible for a federally supported prenatal nutrition program, 100,000 families would no longer get day-care services, and more than half of the 5.8 million pupils in compensatory education programs would be dropped if the budget cuts are approved.

The CDF estimated that President Reagan's proposed fiscal 1983 budget would cut $8 billion from the $49.1 billion in federal aid for welfare, health, nutrition and education programs that benefit children. These spending reductions would be in addition to $10 billion in fiscal 1982 cuts in these programs, the CDF estimated.

Edelman said Reagan has "preyed on the fears and resentments of those Americans who want to believe that most welfare recipients cheat--they don't--and implied that if we just end fraud and abuse in these programs, we will solve our economic problems. What he has not told the American public is that 70 percent of the welfare 'cheats' he is ridding us of are children."

The 216-page analysis of Reagan's fiscal 1983 budget that the CDF released yesterday provides one of the first comprehensive efforts to go through its fine print and calculate the cost of the cuts to individuals.

At a time when the debate in Washington over the new budget is largely focused on the size of the deficit, the Children's Defense Fund report highlights spending reductions that will have the effect of:

* Reducing the number of meals and snacks served in day-care centers. Before the cuts, they served three meals and two snacks daily. Now there are funds for two meals and one snack a day.

* Ending the Summer Feeding Program for children by the summer of 1983. About 1 million poor children are expected to get meals in this program in the summer of 1982.

* Eliminating food stamp and Medicaid benefits for upwards of a million people because of cuts and new eligibility requirements.

* Cutting from $3,600 to $2,000 a year the federal assistance low-income families get for housing.

The working poor have been among those hit hardest by budget cuts already approved, Edelman said, and this is likely to continue if President Reagan's new cuts are approved.

The case of Sharon Haller, a rural Ohio woman with three children who quit her job driving a school bus rather than lose benefits, is one of several examples the Children's Defense Fund report cites. Haller quit her job after determining that under the new Reagan welfare policies she would gain only $1 a month in welfare benefits by continuing to work but lose $9 a month in food stamps and the Medicaid card entitling her and her children to free medical care.

The report also attempted to trace the widely varying methods to which states have resorted to absorb the costs of cuts approved last summer. Six states, Washington, Oregon, Missouri, Kentucky, Iowa and Utah, have eliminated Medicaid benefits for children living at home with both parents.

Virginia is proposing to stop coverage completely for blind and disabled children under 18. South Carolina is proposing limiting the number of hospital days paid by Medicaid to 10; Tennessee is proposing that they be limited to 14 days; Maryland has a 20-day limit. "What Reagan has not told the American public is that 70 percent of the welfare 'cheats' he is ridding us of are children," Edelman said.

The report found similar disincentives to work in the changes the administration is making in the food stamp program. A working family that earns $5,000 a year will get from $300 to $400 a year less in stamps than the family that receives $5,000 a year from welfare or unemployment compensation. This is because a working family's benefits will be tied to its gross wages under the changes and no consideration will be given to the fact that a portion of that income is withheld as taxes or consumed by work-related costs.

In combing through the fine print of the budget, CDF found that the administration in cutting various programs had made in one place or another these assumptions: that the poor should pay 35 percent of their income for food, 30 percent for housing and 25 percent for home energy. The fund noted that these costs alone add up to 90 percent of the poor family's income.

The CDF estimates that 150,000 families will no longer be eligible for federally aided day care because of cuts already made and that another 100,000 will be cut from the program next year if Reagan's new budget is approved.

According to the report, states are handling these reductions in widely differing ways. In Washington state, working families with incomes that are 38 percent above the state's median are no longer eligible for day care. Pennsylvania families can earn up to 90 percent of that state's median.

In Massachusetts, the state Department of Social Services eliminated slots for one-third of the preschool-age children in day-care programs and replaced them with slots for school-age children. In Albany, N.Y., parents earning $8,000 a year must now pay $800 annually for day care.

Edelman proposed as alternatives to the cuts Reagan is proposing a number of reductions in spending and tax breaks, including the oil depreciation allowance, various agricultural subsidies and a wide array of military programs.

She noted that the 1983 budget contains an $800,000 increase in residential expenses for the White House.

"While we want President and Mrs. Reagan to live comfortably, we would prefer to use the proposed annual increase toward replacing 40 percent of the child abuse prevention services which the president proposes to cut," she said.

In a section of the report entitled "Bombs Over Babies," Edelman has these other suggestions:

* That the Defense Department cease sending routine, non-priority messages by teletype, which the General Accounting Office has estimated could save $20 million a year. These funds could be used to restore cuts of about $23.9 million in programs for handicapped children, she said.

* That the taxpayer subsidy of $12.06 for every meal served in Secretary of Defense Caspar W. Weinberger's private dining room be eliminated and that the secretary and his guests be required to pay the full cost of the food they consume. Each subsidized lunch served in Weinberger's dining room, she said, costs the taxpayers about the same as it does to serve 40 low-income children a morning snack of orange juice and crackers.

* That the program of providing personal servants to 300 senior officers at the Pentagon be ended and the money be used to restore funds for 160 homemaking aides in Virginia. Funds for those aides who had served 2,500 aged, blind and disabled persons and families with handicapped children were cut by Reagan last year.

* That the Defense Department no longer provide shots and other veterinary services for the pets of military personnel and that the $1.4 million now spent for that program be used to restore funds to immunize 35,000 poor children who were cut from the childhood immunization program last year.