U.S. life span tops 76 years as infant mortality rate falls

The infant mortality rate in the United States has fallen to an all-time low, while life expectancy at birth has reached a new high, at 76.1 years.

In 1996, there were 7.2 infant deaths per 1,000 live births, according to a summary of preliminary 1996 government statistics published in the December issue of Pediatrics, the journal of the American Academy of Pediatrics. That's 5 percent lower than in 1995 and the lowest ever recorded in the United States.The life expectancy for children born in 1996 was 76.1 years, or 0.3 years longer than in 1995, according to the summary, which was based on data from the National Center for Health Statistics and the Census Bureau.

Medical developments were the main reasons for the decline in the infant mortality rate, said lead author Dr. Bernard Guyer of Johns Hopkins School of Hygiene and Public Health in Baltimore.

But while scientific progress is keeping more children alive, it is also contributing to the growing number of infants with low birth weights - 7.4 percent of all births in 1996, up from 7.3 percent in 1995 and the highest level reported since 1975.

The traditional risk factors did not appear to be to blame. Smoking during pregnancy was down, and early prenatal care rates were up.

Instead, the trend was attributed to increased use of fertility treatments and the growing number of women in their 40s giving birth.

Fertility treatments and giving birth late in life raise the chances of multiple births, which almost always result in premature, underweight babies. Also, individual babies born to older women are more likely to be underweight.

"It is a problem we have created ourselves with our technology," Guyer said.

The number of multiple births has been increasing by an average of 2 percent per year since 1980, according to the report.

The report also noted the fifth consecutive drop in the birth rate for teenagers in 1996, including the first substantial decline for Hispanic teens.