Study Finds Premature Infants to Have Long-Term Complications

Premature birth, and the corresponding survival rate, are on the rise in the United States, and a new study shows that the health consequences are broader and more long-term than initially suspected. One in eight infants in the United States are born prematurely (37 weeks or less), translating to more than half a million babies per year. These pre-term births are not only the prime cause of infant death in the Western world, they are also responsible for a host of physical and neurological complications with long-term effects.

While it is unclear why the rate is so high, a portion of premature births could be due to the rise of assisted reproduction, which often results in multiple births with a greater likelihood of premature delivery. Induced premature deliveries and caesarean sections are also on the rise; many due to distress to the baby or mother, but others out of convenience for the mother or doctor.

The first hours and days set the stage for these tiny infants, commonly referred to as "preemies." Even if they survive the critical time following birth, preemies can develop a wide range of health problems since their organs haven't had time to develop in the womb. These include lung diseases, cerebral palsy, neurological problems, and learning disabilities.

The study, published in the Journal of the American Medical Association (JAMA), tracked 1,167,506 people born in Norway from 1967 to 1988 using birth and medical care records. They also looked at reproduction and educational achievement in the group born from 1967 to 1976. All were single births; approximately 5 percent of which were premature. The study followed the children through 2002.

Researcher Dr. Geeta Swamy of Duke University Medical Center in Durham, North Carolina, and colleagues found that, as a group, the premature babies experienced more long-term risks than did full-term babies. Some of their findings:

• While the overall risk for death among preemies was low, it was significantly higher than for full-term babies.

• Preemies had a higher risk of death in childhood, up to 7 times the normal risk of full-term babies.

• Reproduction rates as adults were affected. Males born at 22 to 27 weeks were 76 percent less likely to have offspring, while those men born at 28 to 32 weeks were 30 percent less likely. Women born at 22 to 27 weeks were 67 percent less likely, and at 28 to 32 weeks were 19 percent less likely than their full-term peers to have their own children.

• Preemies also showed a slightly lower educational achievement than the full-term babies.

"When a family has a pre-term baby, they're pretty concerned and aware of what's going on in those first few months, first years of life. It may be that they need to keep that heightened awareness that there may be other things we should watch out for," Dr. Swamy said in a telephone interview.

Dr. William Benitz, chief of the division of neonatal and developmental medicine at Lucile Packard Children's Hospital at Stanford University said the study is an important paper "because it documents something we have all known in our hearts, that being born premature has enduring implications. Most of the babies do pretty well in the long run. But a substantial portion of them have problems."

But Dr. Swamy wonders, "Are we improving their survival at the expense of significant problems down the road?"