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Babies Born Just a Few Weeks Too Soon at Greater Risk of Cerebral Palsy and Other Developmental Delays

WHITE PLAINS, NY, DEC. 11, 2008- Babies born just a few weeks prematurely are more than three times as likely to have cerebral palsy than full-term infants- adding to the mounting evidence that the last few weeks of pregnancy are critical to a child's health and development.

The research, "Increased Risk of Adverse Neurological Development for Late Preterm Infants," by Petrini et. al. was published online today by the Journal of Pediatrics. The authors also found that late preterm infants, (those born 34-36 weeks gestation), had a higher risk of developmental delays than babies born full-term.

The team of researchers from the March of Dimes, Kaiser Permanente Medical Center, Columbia University and the Harvard School of Public Health analyzed the medical records of more than 140,000 children born in California between January 2000 and June 2004 who had at least one follow-up doctor visit. These children had health insurance coverage through the Kaiser system and as a result had access to preventive care, diagnostic tests and treatments."

The earlier an infant was born, the higher the risk of some neuro-developmental problems, the researchers found. For example, infants born between 30 and 33 weeks gestation were nearly eight times as likely as full-term infants to have cerebral palsy.

"The significantly higher rates of cerebral palsy and developmental delays for late preterm babies were surprising," said Joann Petrini, PhD, director of the March of Dimes Perinatal Data Center and lead author of the study. "Our research adds to the growing body of evidence showing that being born just a few weeks too soon can have lasting consequences that can no longer be described as temporary or benign. These findings reinforce the March of Dimes message that a few extra weeks of pregnancy can have a beneficial effect on an infant's health."

"Since brain development continues through the first year, these findings suggest that some late preterm infants may benefit from neurological assessments by their pediatricians to determine whether there is a need for specialized services," said Gabriel Escobar, MD, of the Kaiser Permanente Division of Research in Oakland, Calif. and a co-author of the study. "Future research should focus on how at-risk late preterm infants can be identified sooner, as neurological screening of all late preterm infants is not feasible."

More than half a million babies are born too soon each year in the United States and the rate of premature birth has increased almost 20 percent since 1990. Late preterm babies account for more than 70 percent of all preterm births and for the majority of the increase in preterm birth rates during the past two decades. Late preterm infants have a greater risk of breathing problems, feeding difficulties, temperature instability (hypothermia), jaundice, delayed brain development and death than babies born at term. This new analysis shows that these late preterm infants also have three times the risk of cerebral palsy and a slightly higher risk of mental retardation.

Exactly what causes the increased risk of cerebral palsy and neuro-developmental delays in late preterm infants cannot be determined from this study, and should be the subject of future research, the investigators said. However, there are several theories, including risk factors during the pregnancy that may contribute to damage in utero, or complications related to the preterm birth.

The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well-being and to improve the quality and cost-effectiveness of health care. Currently, DOR's 400-plus staff is working on more than 250 epidemiological and health services research projects.

The March of Dimes is the leading nonprofit organization for pregnancy and baby health. With chapters nationwide, the March of Dimes works to improve the health of babies by preventing birth defects, premature birth and infant mortality. For the latest resources and information, visit marchofdimes.com or nacersano.org. And for detailed national, state and local perinatal statistics, visit PeriStats at marchofdimes.com/PeriStats.