"Preterm infants are generally considered more difficult temperamentally than full-term infants in the first year of life," says study author Mary B. Hughes, Ph.D., R.N., formerly of the University of Pennsylvania and now at Rutgers University College of Nursing.
"But temperament in preterm infants has not been examined before 3 months of age, a time that is perhaps most problematic for parents as they adjust to caring for their infant at home," she adds.
Premature infants, known as preemies, come into the world early, at 37 weeks after conception or earlier, while full-term infants are born at 38 to 42 weeks. Preterm infants are reported to display intense moods, withdraw when exposed to new situations, and be irregular in their bodily functions.
Hughes and colleagues studied 74 preterm infants and asked their mothers to rate the infants' temperaments. The researchers then compared the temperament scores of the 6-week-old preterm infants to standardized scores of full-term infants. Six and 12 months later they compared a subset of the original 74 preemies with full-term infants.
At 6 weeks, the researchers found significant differences between the pre- and full-term infants. The preterm infants were less regular in their bodily functions (such as eating, sleeping and elimination), easier to soothe and distract from discomfort and more withdrawn when exposed to new stimuli.
"Irregularity of biological functions, although an expected hurdle of early parenthood, appears to be more challenging for parents of preterm infants," Hughes says. "This tendency renders their life somewhat unpredictable, making it difficult to plan for daily activities not knowing when the preterm infant's physiologic needs will interrupt the daily flow."
The preemie temperament differences at 6 weeks could be related to their physiological immaturity compared to full-term infants. Hughes notes that further study is needed on that point.
"What we refer to as temperament manifestations in preterm infants may be related to differences in maturity of underlying neurobehavioral processes," Hughes says.
But these challenges unique to preemie parenting didn't last forever in the group studied. By six months of age, the preterm infants differed from the full-term in just one way: They were less adaptable than the full-term infants were.
"Lower adaptability generally requires more attention and patience from parents in helping an infant to negotiate daily activities and adjust to transitions," Hughes notes.
By 12 months, mothers' scores indicated that the preterm babies were less likely than the full-term group to persist in activities when faced with an obstacle. The study findings are published in the December issue of the Journal of Developmental and Behavioral Pediatrics.
"Preterm infants are at risk for overstimulation by parents diligently attempting to connect with their infant," Hughes says. "But infants that become overloaded by environmental stimuli respond by shutting down and tuning out."
She adds, "We need to help parents understand the particular behavioral style of their infant, which will eventually come to look more like the full-term infant's."
The study was funded by the National Institutes of Health.
By Ann Quigley, Contributing Writer
FOR MORE INFORMATION
Health Behavior News Service: (202) 387-2829 or www.hbns.org.
Interviews: Contact Mary B. Hughes at (973) 353-5326, x563, or hughes@nightingale.rutgers.edu.
Journal of Developmental and Behavioral Pediatrics: Contact Mary Sharkey at (212) 595-7717.
Journal
Journal of Developmental & Behavioral Pediatrics