Troubling trends in infant health.

• Position: TRENDS AND TRANSITIONS - Brief article

The number of infants born preterm (less than 37 weeks) has increased more than 30 percent since 1981, according to new data from Research!America, a nonprofit alliance for health research. That means one in eight babies is born prematurely in the United States. Although the increase in premature births is attributed in part to the rising number of multiple births, the alliance notes that half of all premature births have no known cause.

The percentage of infants who are born with low birth weights (less than 2,500 grams) also has been climbing--up 16 percent since 1990.

Prematurity is the greatest risk factor for infant mortality; in 2002, 65 percent of infants who died before age 1 were born prematurely. Black women are nearly twice as likely to have their babies prematurely as white...