TUESDAY, March 25, 2008 (HealthDay News) -- The effects of premature birth last long after a baby leaves the neonatal intensive care unit, a new study finds.
The risk of mortality is increased for years after infancy. And as premature infants grow and try to start families of their own, their own reproductive rates are decreased and women born prematurely have an increased risk of delivering prematurely, the study discovered.
"If you are a parent who has a preterm child, following the first year of life, the mortality risk goes down. But, keep in mind, it's still increased. It's not a cause for significant alarm because the overall rate of mortality is still low, but you need to keep it in mind and make sure you're getting appropriate medical care and surveillance for your child," said study author Dr. Geeta Swamy, an assistant professor of obstetrics and gynecology at Duke University Medical Center.
Results of the study are published in the March 26 issue of the Journal of the American Medical Association.
Premature birth is a delivery that occurs before 38 weeks of gestation. About one in eight births in the United States is premature, according to Swamy. Sixty percent of babies born at 26 weeks of gestation have long-term disabilities, such as chronic lung disease, blindness, deafness and neurodevelopmental problems. For babies born at 31 weeks, that number drops to 30 percent, according to background information in the study.
Swamy said that while a lot of attention has been focused on the serious risks that premature infants face early on, most research hasn't looked at what happens as these babies grow up.
To get an idea of the long-term effects of prematurity, Swamy and her colleagues assessed the health of more than 1 million babies born in Norway between 1967 and 1988. The researchers collected mortality data through 2002, and educational and reproductive outcomes through 2004.
For boys born between 22 and 27 weeks' gestation, the risk of early childhood mortality (between 1 and 6 years old) was 5.3 times higher, and the risk of late childhood death (between 6 and 12.9 years old) was seven times higher. For those born between 28 and 32 weeks, the risk of early childhood death was 2.5 times higher, and the late childhood death risk was 2.3 times higher.
For girls born between 22 and 27 weeks, the risk of early childhood death was 9.7 times higher. There were no late childhood deaths in girls in this gestational age group. Additionally, in girls born between 28 and 32 weeks, there was no increase in mortality rates in childhood.
Those children who survived through adolescence didn't escape effects from prematurity. Men born between 22 and 27 weeks were 76 percent less likely to reproduce, and women born at the same age were 67 percent less likely to have children. Women born prematurely who did have children were more likely to have preterm offspring. No such effect was found for men.
"Prematurity may have caused issues that made them susceptible. Were they left with chronic lung disease? Were they left with cerebral palsy? There's a big belief that we're doing so great now, but premature births are still a big problem," said Dr. Peter Bernstein, a maternal-fetal specialist at Montefiore Medical Center in New York City.
Bernstein added that expectations for today's babies might be brighter because there have been advances in the care of premature infants.
Swamy agreed that the survival numbers may have changed for the better since the study began, but pointed out that the rate of chronic medical conditions could be higher now.
To learn more about preventing preterm labor and birth, visit the U.S. National Institute of Child Health and Human Development.