What was going on when I was born?

''To be very blunt, we now see that unless there is dramatic action, the United States will experience an unprecedented series of deficits during the years ahead.

Rising partisan rivalry in the South, an increased black vote and polarization over unemployment stimulated the relatively high turnout in last Tuesday's voting, reversing a 20-year national trend of declining voter participation in midterm elections, according to voting specialists. Curtis B. Gans, director of the Committee for the Study of the American Electorate, said that although many had expected referendums on the nuclear freeze question in nine states to increase voter interest, there was little evidence that this or any other referendum items had raised voter turnout beyond the overall national pattern. Mr. Gans, whose group is private and nonpartisan, said that over all, the turnout had risen since 1978 in twice as many states as it had declined and that the same proportion had shown up in states where the nuclear freeze issue was on the ballot. The turnout was up in six of those states and down in three. ''Turnout was up because the Democratic base vote had been activated as I haven't seen it activated in 18 years,'' said Vince Breglio, director of the National Republican Senatorial Committee. ''We knew the electorate was polarized. The Democrats were activated and that polarization hurt us in places where the Democratic registration is heavy.''

The U.S. and its allies have all but agreed on a trade policy that will allow the removal of sanctions against companies involved in the Soviet pipeline, according to Administration officials. They said France wants publicity about the agreement held to a minimum so it does not appear to have made any concessions. (Page A1.) Four overseas officials of Pepsico were apparently getting performance-related bonuses before they were dismissed for overstating sales and profits. The company, which will not seek to recover the money, said it had found no indication that the managers' misrepresentations were meant for their personal gain. (D1.)

Representative Dan Rostenkowski, the chief tax writer in the House, declared today that Congress must raise the Federal gasoline tax next year by 5 cents a gallon to pay for ''the massive reparation of the nation's bridges and roads.'' The tax now is 4 cents a gallon. The Illinois Democrat also challenged President Reagan to cut his military budget, which the President has vowed not to do. ''The real choice facing the Reagan White House is between big defense cuts and big tax increases,'' Mr. Rostenkowski asserted.

International A way toward revoking the sanctions imposed by President Reagan on companies that take part in construction of the Soviet natural gas pipeline has been devised, according to Washington officials. They said the Administration would be able to end the sanctions under a new policy for East-West economic relations virtually agreed upon by the United States and its European allies. (Page A1, Col. 6.) The American envoy to El Salvador has been ordered to refrain from making public criticism of human rights abuses by Salvadoran security forces, according to Reagan Administration officials. The Ambassador, Deane R. Hinton, had assailed the Salvadoran legal system and acts of violence by right-wing extremists. (A1:4-5.)

Mayor Koch said yesterday that New York City could probably balance its budget this year and next without laying off any workers. However, the Mayor, in a day of statements on the subject that left even some of his own aides uncertain of his position, stopped short of promising that no layoffs would occur. He said he reserved the right to dismiss workers as a ''last resort.'' The decision depends, he said, on other factors, such as the amount of city revenues from current sources, the passage of a new tax package he plans to submit to the State Legislature and the cooperation of municipal labor unions in cost saving.

A young challenger for the presidency of the United Mine Workers, Richard L. Trumka, swept to a resounding victory tonight over the 46-year-old incumbent, Sam M. Church Jr. Mr. Trumka won in a race that had been expected by union officials to be extremely close. In the preliminary totals issued by tellers at the union headquarters, with 651 of the 868 locals reporting, Mr. Trumka was leading Mr. Church by 72,896 to 34,399. Winning with Mr. Trumka by about the same proportion was his vice-presidential running mate, Cecil Roberts.

A listing last Thursday of the members of the House of Representatives for 1983 incorrectly named the winners in two Virginia districts. The Fifth District will be represented by Dan Daniel and the Sixth by James Olin. Both are Democrats.

Government regulations announced today would let taxpayers avoid having taxes withheld from their interest and dividends by dividing their savings and investments among several small accounts. The regulations, which take effect when withholding from interest and dividends begins next July 1, permit financial institutions to forgo withholding from any account that earns no more than $150 a year. Under the tax law authorized last summer, an individual purchasing a $5,000 certificate of deposit earning $500 a year is liable for 10 percent withholding on the interest. However, under the new regulations issued by the Internal Revenue Service, withholding might be avoided by buying five $1,000 certificates instead.

''Why, I've never seen anything like that before,'' King Carl XVI Gustaf of Sweden said yesterday as he peered at an artifact in the Museum of American Folk Art. The King was in the museum, at 49 West 53d Street, with his wife, Queen Silvia, to view material from a Swedish-American settlement called Bishop Hill that flourished in Illinois in the last century. Bishop Hill was known for simple but ingenious tools, among other things, and the King was intrigued by a dough mixer rotated by a bow with a string wrapped around the beater shaft.

IT was not one of those upper East Side cocktail parties where everyone asks, ''What do you do?'' Since half the couples were expecting babies, the question of the hour was, ''When are you due?'' The rest of the couples were new parents, and their babies, an even dozen, were passed around the room like tiny pink canapes so the mothers-and fathers-to-be could practice holding them. The expectant parents, who looked at once enthralled and terrified by the babies, kept saying things like, ''Such little feet'' and ''Was he born with that much hair?'' The new parents, who had been in the business for two months, looked proud and a bit blase. They said things like ''Babies have a mind of their own'' and ''You won't be getting much sleep for a while.'' The link between the two groups was the hostess, Christina Steifel Conta, a cheerful figure in a pink smock who has the ability to burp a baby while pouring wine. She is a clinical nurse-specialist in perinatology at New York Hospital and she teaches a private sevenweek course for couples in the Lamaze birth method.

INSTEAD of spending an ever-increasing share of the weekly budget for the same amount of groceries - as American shoppers have been doing almost a decade - it has actually been possible in the last few weeks to walk out of the supermarket with a few pennies left over. Consumers have been able to find bargains in frequent specials on beef and lower prices for chicken, apples, potatoes, rice and pasta. Those are just a few of the items that are and will continue to be significantly less expensive this year than they were in 1981. In addition, citrus fruit will be coming to market in greater quantities and at good prices within a few weeks, brussels sprouts will remain at the peak of their season and November through January is the best time for avocados. The recession - which has led to high unemployment and a consequent reduction in buying power - and a year of good to excellent harvests for most farm products have exerted downward pressure on food prices. That does not mean that shoppers are paying less for everything than they did a year ago, but those who shop carefully can make significant dents in their food bills.