Scientists Confirm Link Between Premature Birth And Later Learning, Behavioral Problems

The scientists call for "concerted efforts of clinicians and neuroscientists to [study] the biological, environmental, and psychosocial mechanisms responsible for these cognitive and behavioral differences."

Children born prematurely have been found in numerous studies to have "huge differences" in cognitive scores, and to be aggressive or withdrawn or suffer from attention deficit hyperactivity disorder. However, researchers who conducted the other studies over the years used a variety of population groups and research methods, making the body of knowledge about the effects of pre-maturity questionable.

K. S. "Sunny" Anand, MBBS, D.Phil., FAAP, FCCM, FRCPCH, led the study, called a meta-analysis. Dr. Anand is the Morris and Hettie Oakley Chair in Critical Care Medicine in the Department of Pediatrics in the UAMS College of Medicine and chief of critical care at Arkansas Children’s Hospital. The National Institute for Child Health and Human Development and the Blowitz-Ridgeway Foundation provided research funding to the Arkansas Children’s Hospital Research Institute for the study.

The scientists analyzed 227 studies, eliminating studies that had methodological problems, before drawing conclusions from the remaining studies. Their analysis should "eliminate controversies" about the importance of pre-maturity for long-range outcomes.

While the relationship between pre-maturity and later learning and behavioral problems is now clearer, the actual causes of those problems in children born prematurely are not yet clear.

The UAMS investigators speculate in JAMA that the medical complications of pre-maturity; the painful medical procedures that many premature babies experience in hospitals; and prolonged separation from their mothers all may contribute to lower-than-average brain development and thus to later learning and behavioral problems. They also point to the stress and depression that having a premature baby can cause for parents, particularly mothers, as a potential factor in the children’s later developmental problems.

Dr. Anand commented recently that the increasing survival rate for extremely low birth weight and premature babies means that "a larger and larger pool of children" will have developmental problems "as times goes on … and the incremental costs of educating these children are likely to be astronomical."

"With an improved understanding of the underlying biological mechanisms, we can begin to develop more focused therapeutic interventions to decrease or prevent these long-term impairments following survival after pre-term birth," the scientists conclude in JAMA.

The following investigators, all with UAMS, collaborated with Anand: Adnan T. Bhutta, MBBS, FAAP, assistant professor of pediatrics; Mario A. Cleves, Ph.D., associate professor of pediatrics and senior bio-statistician, Arkansas Center for Birth Defects Research and Prevention; Patrick H. Casey, M.D., FAAP, the Harvey and Bernice Jones Professor of Developmental Pediatrics; and Mary M. Cradock, Ph.D., assistant professor of pediatrics. The researchers formulated a novel method for assessing the quality of observational studies which other scientists will now be able to use.

Anand also is conducting multiple studies of the relationship of pain to brain development in premature infants. By observing the progress of premature infants who receive pain medication in conjunction with painful medical procedures, and through laboratory experiments, he has formed the hypothesis that repetitive pain in the first weeks of life causes the death or damage of certain brain cells and may consequently reduce learning ability and alter behavioral development. As part of this research, Anand is participating in a nationwide study of the use of pain medication to reduce or eliminate pain during essential medical procedures for premature infants. The National Institutes of Health are sponsoring the study at 11 centers around the nation and four hospitals in Europe.