CHAMPAIGN, Ill. -- For mothers of premature, very low birth-weight babies
that began life in the sterile confines of a neonatal intensive care unit,
the second year of motherhood may bring new stresses and a barely 50 percent
chance that a secure bond will form with the children, researchers report.
The findings provide new insight on how medical technology's ability to keep increasingly younger babies alive may impact early cognitive development. Researchers gathered information about 37 babies, who weighed an average of 2 pounds at birth and were born 13 weeks early in the normal 40-week gestation period.
The findings were detailed in the September issue of Developmental Psychology by Sarah Mangelsdorf, a professor of psychology at the University of Illinois; Jean L. McHale, a former U. of I. graduate student in psychology; and University of Michigan researchers James Plunkett, Cynthia Dedrick, Meryl Berlin, Samuel Meisels and Margo Dicthellmiller. Previous studies had found little difference in the quality of parent-infant attachment between premature infants of less risk and normal infants.
The researchers observed infant-mother interaction in homes and in a laboratory. All of the infants had spent an average of three months in intensive care at the University of Michigan Hospital and had survived without serious physical or neurological complications.
Most troubling, Mangelsdorf said, was a decline in the rates of secure parent-infant relationships in the first two years. "At 19 months, 75 percent of normal full-term babies were rated as secure, but attachment security for very low birth-weight babies was just under 50 percent. At 14 months, the distributions of the two groups were about the same, but there was a shift to insecurity at 19 months."
Based on the mothers' self-report data on the impact of the infants on their families, Mangelsdorf theorizes that a decline of professional and informal support after a child goes home may allow for new stresses. "The second year may in fact be harder on the parents," she said. "Parents tend to compare their child with others in the same age group rather than with other premature babies; they see their child as behind developmentally.
"There is a huge variability in the outcome of these kids, but I am struck by the remarkable resilience of the human organism," she said. "Some of these babies were the size of your hand when they were born, and they had been hooked up to machinery to keep them alive. Yet we later saw them running around in the lab at 3 years of age. When my student coding the videotapes tried to guess which kids in our sample had been premature and which had not, her guesses were no better than chance."
Unpublished data show that while the premature infants performed significantly lower on measures of cognitive development through age 3 than did full-term children, they still scored in the average range. In an earlier paper, the researchers suggested that parental education programs to increase knowledge about child development may help parents enhance the developmental outcomes of infants born at risk.