Premature birth has lasting effects, study finds

Researchers already knew that premature infants faced many neurological and developmental problems, but the new findings to be reported Wednesday indicate that the spectrum of problems is even broader than suspected and persist throughout the child's lifetime.

The study, conducted using Norwegian birth data, suggests that, as the percentage of premature infants who make it through their first year continues to grow because of advances in neonatology, the number of troubled infants and adults will also rise.

"Are we improving their survival at the expense of significant problems down the road?" asked the lead author, Dr. Geeta Swamy of the Duke University Medical Center.

Experts said the situation is probably worse in the United States.

"Norway demonstrates better outcomes than the United States, which has persistent, stark racial disparities" in care for the premature, wrote Melissa M. Adams of RTI International in Atlanta and Dr. Wanda D. Barfield of the Centers for Disease Control and Prevention in an editorial accompanying the report in the Journal of the American Medical Assn.

One in eight American infants is now born prematurely, a total of more than half a million per year, despite the best efforts of physicians to bring more pregnancies to full term -- defined as 38 weeks or longer.

Researchers are not sure why the rate is so high, but contributing factors include the growing incidence of assisted reproduction, which often produces twins or triplets, which are more likely to be born prematurely.

There is also a rising incidence of deliberately induced premature deliveries and Cesarean sections -- many because of distress to the mother or infant, but some for the convenience of doctor or mother.

The consequences can be devastating, particularly for very early births. They include learning disabilities, neurological problems, lung diseases and cerebral palsy.

Using Norway's extensive registry of births and medical care, Swamy and her colleagues studied all 1,167,506 singleton births in that country between 1967 and 1988, following the children through 2002. They also looked at educational achievement and reproduction in the group born between 1967 and 1976.