April 3 - Though the majority of children born prematurely grow up healthy, a new Norwegian study reveals new findings on possible consequences of prematurity in addition to known outcomes such as higher risks of dying during the first year, lung problems, disabilities, mental retardation, and educational delays.

The study, which recently appeared in the Journal of the American Medical Association, found that children born early suffer higher death rates in childhood. Children born five to nine weeks early have double the risk of death from ages 1 to 5 compared with children born full term; researchers found greater risk for boys, although the overall risk of death is low.

Other differences appeared beyond childhood. Prematurity was linked to lower levels of education and more childlessness in both men and women. Also, women who were preemies themselves had a higher risk of giving birth to premature babies.

In the U.S., the rates of premature births have climbed steadily during the past two decades, reaching an estimated 12.8 percent in 2006. The main culprits for the rise appear to be fertility treatments that result in multiple births and women delaying childbirth.

In 2006 the Institute of Medicine released the report Preterm Birth: Causes, Consequences, and Prevention, which examined the high rate of premature births in the United States and its costs, as well as the troubling disparities in preterm birth rates among different racial and ethnic groups. The report recommends a multidisciplinary research agenda aimed at improving the prediction and prevention of preterm labor and understanding of the health and developmental problems to which preterm infants are more vulnerable. In addition, the report recommends that guidelines be issued to further reduce the number of multiple births -- a significant risk factor for preterm birth -- resulting from infertility treatments.

• Preterm Birth: Causes, Consequences, and Prevention

• National Institute of Child Health and Human Development