Babies Born Underweight Become Stressed Adults
Study finds problem extends well into adulthood
FRIDAY, Oct. 4, 2002 (HealthDayNews) -- As if the deck isn't stacked enough against those born small, research now shows tiny infants are more likely to face psychological problems as adults.
The same holds true for children whose weight gain is slow in the early years of life, Singapore researchers report in tomorrow?s issue of the British Medical Journal.
Moreover, those born underweight who also experience slow weight gain in childhood have a 20 percent higher risk for psychological problems as adults than those born a regular size whose weight gain is on par with others their age.
The researchers don't know why weighing less predisposes someone to psychological difficulties, but "we are interested in the hypothesis proposed by previous researchers that growth failure relates to brain development, which affects stress hormones in later life," says lead researcher Dr. Yin Bun Cheung of the National Cancer Center in Singapore.
The researchers followed 9,731 British babies born in 1958 for 42 years. Information was obtained related to their weight at birth and in childhood, and they were assessed for risk of developing psychological problems at ages 23, 33 or 42.
Overall, 59 percent of the subjects were included in this final analysis. To assess psychological difficulties, the adults were asked to complete a self-administered questionnaire that evaluates those considered at higher risk for psychiatric illness.
Children born about 1.1 pounds less than average who grew normally throughout childhood had an 11 percent greater likelihood of developing psychological problems than children who were not underweight at birth and who grew normally, Cheung says. Similarly, the risk for psychological problems was 8 percent higher for a child of normal birth weight who gained around 7.7 pounds less than the average 45.1 pounds most children gain from birth to age 7.
Children who were born small but had a faster-than-average weight gain in childhood were not more likely to be at risk for psychological distress, since the childhood spurt seems to balance out the risk associated with low birth weight, he says.
Cheung says his research team conducted an earlier study that showed young adults born small had more psychological distress. This study shows the increased risk extends into later adulthood.
Dr. Lynne M. Haverkos, a behavioral scientist with the National Institute of Child Health and Human Development, says many other factors that could lead to psychological problems later in life were not taken into consideration in this study. "It does not mention medical problems and stress life events encountered by the study participants and their families," she notes.
She believes more studies into low birth weight babies are required before it's known exactly why they may experience more psychological problems as adults, and if low birth weight is really the underlying reason for the later distress. "Low birth weight babies who had serious medical problems requiring extensive medical treatment were exposed to additional physiologic stresses and to a variety of parental responses, one of which could be protective parenting," she says. "We're still learning about the long-term effects of stress on individuals and families."
Cheung says he plans more studies: "We are now exploring whether growth affects actual diagnosis of psychological disorders."
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