The nation's fertility rate fell to a record low last year, while life expectancy reached a record high and marriage and divorce rates dipped to the lowest levels in a decade, a new government report shows.

Average life expectancy "in 1986 reached a new record high of 74.9 years," said the Center for Health Statistics, an arm of the Department of Health and Human Services. That was up from 74.7 years reported in 1985.

The highest life expectancy was 78.9 years for white females, up from 78.7 a year earlier. White males saw an increase from 71.8 to 72.0 years.

Black life expectancy rose from 65.3 to 65.5 years for men, but declined from 73.7 to 73.6 years for women, the center's annual summary of vital statistics reported.

Births totaled 3,731,000, down 18,000 from 1985.

That represented 64.9 live births per 1,000 women aged 15 to 44, 2 percent below last year and the lowest rate ever recorded in the United States, the report said.

The drop reflects the trend of recent years, as many young people have postponed marriage and families to pursue education and careers.

Social scientists have debated in recent years whether this represents merely a delay in having children or a decision not to have families. Only time will disclose the answer as the children of the post-World War II baby boom pass through their prime childbearing years.

The number of women aged 15 to 44 increased 1 percent between 1985 and last year, but the bulk of that was among women aged 30 and over, whose birth rates tend to be lower. The number of women aged 15 to 29 declined by 1 percent.