THURSDAY, March 15 (HealthDay News) -- When parents of very small premature infants are stressed or depressed, their children are more likely to develop behavioral problems by age 3, according to new research.

What's more, the worse the parents scored on psychological well-being indicators, the more likely their youngsters were to develop the problems.

"The psychological well-being of both parents is a significant contributor on the behavioral and emotional development of preterm children," said study lead author Dr. Mira Huhtala, a researcher at Turku University Hospital in Finland.

Results of the study, scheduled to be published in the April print issue of Pediatrics, were released online March 12.

Babies born prematurely have a greater risk of behavioral, emotional and neurological problems, probably for multiple reasons, according to this study.

Preemies endure a great deal of stress in the neonatal intensive care unit, noted Dr. Deborah Campbell, director of neonatology at Montefiore Medical Center in New York City. While it's not clear exactly how that stress might affect a baby, Campbell said it may cause changes in the developing brain. She said that preemies also have smaller brain volumes on average, and overall they're just not as developed as they should be.

At the same time, their parents are incredibly stressed and less resilient. The premature birth of their child may lead to lowered expectations, and they may be overly fearful, which may limit the child's opportunities for normal development, she noted. If parents are depressed or feeling a sense of loss, they may not engage or connect with the child as well, said Campbell.

"It's difficult to know how much of behavior is from underlying biology and how much is the influence of the family," she said.

In an attempt to tease out which factors might matter more, Huhtala and her colleagues evaluated 140 parents of very low birth-weight children born before 37 weeks of gestation (40 weeks is considered full-term). Very low birth weight means a baby weighs less than 1,500 grams (about 3.3 pounds) at birth.

Background data was collected on the parents at the time of birth. When the babies turned 2 years old, their parents were asked to complete psychological well-being questionnaires, and researchers assessed the children's behavior. Just before the children's third birthday, parents completed a questionnaire about the child's behavior.

Parents were assessed for depression, stress and "sense of coherence." Sense of coherence is "readiness to successfully coordinate and take advantage of personal resources," according to the study.

"The more symptoms of poor psychological well-being (depressive symptoms, parenting stress, or weak sense of coherence) the mothers or fathers experienced, the more behavioral problems their children developed as reported by the parents," Huhtala said. "The study showed that not only the psychological well-being of the mothers but also that of the fathers contributes to the behavioral problems of preterm children."

Still, aggressive behaviors and attention problems tended to be more related to the mother's psychological well-being, Huhtala added. This may be because fathers find it easier to tolerate these kinds of behaviors, she suggested.

Stress is normal after a premature birth, and the study doesn't show a cause and effect relationship between stress and behavioral issues, merely an association.

Huhtala recommended that parents seek out psychosocial support if they have trouble coping after having a preterm baby.

Campbell agreed that it's important to seek support. If you don't have a family member or friend that you feel you can talk to, she recommended talking to your doctor or your child's doctor. She said it may be harder for men, but it's important to seek help. Many parents who've had a very premature infant "basically have post-traumatic stress disorder," she said, and they have to deal with feelings of guilt, and they need to grieve the loss of the life they had imagined for their child.

The issue of prematurity is often a lifelong process, Campbell said. Parents may think they've gotten over the worst of it when they get their baby home, but then the child may have problems when school starts. "For each issue that comes up, parents have to grieve again," she said.

More information

Learn more about coping with a premature birth from the March of Dimes.