The rate of infant deaths in Washington increased last year, giving Mayor Marion Barry an apparent setback in his widely publicized efforts to lower the city's infant mortality rate, which he once called the city's Number One health problem."

In 1980 there were 24.6 deaths for every 1,000 live births in Washington compared with 22.2 in 1979 and 25.8 in 1978, James A. Buford, Department of Human Services director announced yesterday. The rate is among the highest for any city in the country.

In 1979, 9,403 children were born in the District and 207 died in the first year of life. Last year, 9,257 were born, and 228 died, an increase of about 10 percent over the previous year.

"I think the reason for the increase for the most part has to do with the fluctuations in the trends," Buford said. He said there is an overall downward trend in infant motality in the District since the early 1970s.

According to city figures, the average annual infant mortality rate for the years 1970-72 inclusive was 28.2 for every 1,000 live births.

Acting health commissioner Dr. Martin Levy said he did not believe the 1980 increase is statistically significant, meaning that the change in the rate is too small to determine if the increase represents a reversal of the overall downward trend.

Others saw the increase as more important, reflecting on the city's health care programs for pregnant women.

"Based on continuing meetings locally, I'm not surprised that there was a slight increase," said Dr. Lennox Westney, director of obstetrics at Howard University Hospital. He said that they city's programs to care for pregnant women are not well coordinated.

He said women with troublesome pregnancies, for example, receive regular care at community clinics instead of at the hospitals where they will give birth. Therefore, said Westney, physicians do not have records of the kind of care the woman has received in the past.

Westney said most infants die within the first 24 hours of life because they are born too early and their vital organs are not mature enough to sustain them outside the womb. Pregnant women who eat poorly, develop urinary tract infections, use drugs, are under stress or have hypertension are at a greater risk of having a premature baby, Westney said.

Dr. Ishild Swoboda oversees the District's $5.5 million clinic program for pregnant women, which includes 11 DHS prenatal clinics. She said the most significant problem continues to be getting women to go to the doctor during the first three months of pregnancy.

Swoboda said many high-risk mothers live in wards 6, 7, and 8, which include most of the poorest sections of Northeast and Southeast Washington. She said outreach efforts have been concentrated in these areas and include a visiting nurse program and educational projects in the public schools.

However, Swoboda said, the programs are hampered by a limited budget, which has not increased since 1973.

The national infant mortality rate for 1979 -- the last year for which complete statistics are available -- was 13.8 deaths for each 1,000 live births. In Virginia, the rate for the same year was 14.2; in Maryland 12.4.

A statement handed out by Buford's office said "straight comparisons of District infant mortality figures to national figures do not present an accurate picture. Nationwide, the rate for black infants is 76 percent higher than for white infants, a figure which has remained constant since 1940." Buford also said a high infant morality rate is caused by a concentration of poor people, not race.

Last June, the mayor's Blue Ribbon Committee on Infant Mortality submitted its plan to lower the rate. But yesterday, Buford said that only about one-third of the committee's suggestions have been put into action. Future plans include the use of a mobile prenatal clinic and a nutritional program.

City officials are, however, making efforts to get new programs off the ground. Mary Lampson, special assistant to Mayor Barry, said the mayor will announce today the formation of a new 23-member infant mortality advisory board to pool all program recommendations and put them to work using government as well as private resources.

In addition, Dr. Levy said he hopes that by the end of the week a new supplemental food program for women and infants will be introduced. Under the plan, pregnant women with recognized health problems will receive food vouchers from city-run clinics and some private agencies for items like juice, fresh fruit, eggs, milk and infant formula.