Two prominent Republican campaign consultants are circulating a study of the increase in women's voting that shows a growing peril to President Reagan's 1984 reelection chances, particularly in the South.

The study is expected to heighten the political concerns that have made women's issues a matter of major attention at the White House in the last two weeks.

Using Census Bureau surveys on voting turnout in the last four elections, Vincent Breglio and Susan Bryant have pinpointed five southern states where the impact of women's voting has increased more significantly since 1976 than in any of the other 25 most populous states. The states are North Carolina, Georgia, Kentucky, Alabama and Tennessee.

Virginia, Louisiana, Florida and Texas are also states where the influence of women at the polls has grown markedly, the two consultants have found. Of these nine states, Reagan carried all but Georgia in 1980.

The growing impact of the women's vote in the South, measured and detailed for the first time in the Breglio-Bryant computer analysis, adds to concerns many Republicans have expressed about the potential for significant increases in black voter registration in that region. Women have persistently given Reagan lower approval ratings than men, and the president's black support is minimal.

"You put the two together," Bryant said, "and we Republicans have a serious problem."

That view is known to be shared, at least to some degree, at the White House. Edward J. Rollins, Reagan's top political assistant, was reported to have told Republican National Committee members in Dallas earlier this summer that the South likely would be severely split in 1984, rather than giving virtually all its electoral votes to Reagan as it did in 1980.

But Breglio and Bryant also contend that the trend toward increasing turnouts of blacks and women could jeopardize Republican control of the Senate and make races more difficult for GOP House candidates, not just in that region but around the country.

There are key Senate races, involving Republican-held seats, in North Carolina, Tennessee, Virginia and Texas, all of which appear high on the Breglio-Bryant list of affected states. Mississippi, which was not analyzed because of its smaller population, also has a vital Senate race and probably fits the same pattern, they said.

Outside of the South, Illinois, Iowa and Minnesota are other states where the growing impact of the women's vote could have serious consequences, not only for Reagan, but also for Republican senators expected to face tough reelection challenges next year.

The "gender gap," or inclination of women to give Reagan less support than men do, has been identified as a serious political problem for the president since it showed up as a significant factor in 1980 pre-election polls.

Breglio and Bryant, who in 1982 headed the staff of the Republican Senatorial Campaign Committee, said it was of equal concern to GOP candidates further down the ballot. Bryant said that "of 15 seriously contested Senate races in 1982, only two of the Republican candidates ran as well among women as they did among men."

Those candidates were Sens. Robert T. Stafford (R-Vt.) and John C. Danforth (R-Mo.), and a late slump in support from women almost caused a Danforth defeat by a woman opponent, they said.

The gender gap for both Reagan and the Republicans showed up vividly in the results of the most recent Washington Post-ABC News poll, conducted July 28 to Aug. 1. Reagan had an overall approval rating of 58 percent to 37 percent among men and 47-to-51 percent negative among women. The gender differences were as large or larger on such specific issues as handling of the economy and inflation and the wisdom of U.S. participation in military exercises in Central America.

In trial heats among registered voters of possible presidential match-ups, Reagan led former vice president Walter F. Mondale 54 to 43 percent among men, but trailed him 42 to 52 percent among women. He led Sen. John Glenn (D-Ohio) 49 to 44 percent among men, but trailed him 38 to 55 percent among women.

When asked which party was coping better with the main problems facing the country, men gave the Republican Party a 42-to-38 percent edge, while women gave Democrats a 51-to-30 percent majority.

On a basic question of party identification, 12 percent more women than men said they called themselves Democrats or leaned toward the Democrats, and 8 percent fewer called themselves Republicans or leaned toward the GOP.

Some Republican strategists privy to private polling for the White House have said the gender gap is less visible in southern states, particularly the Deep South, than in other parts of the country. At least in that region, they say, it may reflect Reagan's extra appeal to men as much as it does his relative lack of support among women.

But on most measures, the Post-ABC poll found the gap just as great in the South as in the nation as a whole. While the general phenomenon of increasing participation by women in the electorate had been identified by the Census Bureau and news organization polls, the Breglio-Bryant study is the first to spell out its electoral consequences by tracing the pattern to individual states.

Using unpublished data from the Census Bureau's biennial survey of voting participation, Research/Strategy/Management, the private political consulting firm Breglio and Bryant now head, has reported in its memo that:

In all of the 25 most populous states, women cast more votes than men did in 1980, and in 1982, the pattern was the same, except in Louisiana, where men cast more votes than did women.

In 15 of the 25 states, women had a higher impact on the voting in 1980 than in 1976, and in 17 of the 25 states, women had greater impact in 1982 than in 1978. "There is every reason to think," Breglio said, "that this trend will continue in 1984."

The estimated impact in specific states is dramatic. In Florida, for example, where the presidential vote total increased by more than 400,000 between 1976 and 1980, the calculation is that 129,000 more males but 303,000 more women went to the polls. In Georgia, where the vote total jumped by more than half a million between 1978 and 1982, the Breglio-Bryant estimate is that 217,000 of the additional voters were men and 322,000 were women.

Many of the same southern states spotlighted in the Breglio-Bryant study as areas of recent growth in the women's vote have also seen sharp increases in voting by blacks, who are overwhelmingly negative in their attitudes toward Reagan.

The combination of the two trends, Breglio and Bryant say, could seriously jeopardize Reagan's electoral strategy, particularly since his margins in many of the southern states were shaky in 1980.

In 1980, Reagan carried all of the southern states except Georgia, home state of his rival, President Carter. But his pluralities were less than 40,000 votes in seven of those states--Alabama, Arkansas, Kentucky, Mississippi, North Carolina, South Carolina and Tennessee.

"The South," Breglio said, "is a different political animal today than it was even in 1980. And it is much tougher for us."