By the time they reached adulthood, very-low-birth-weight (VLBW) infants born in the late 1970s lagged behind their normal birth weight counterparts in I.Q. scores and educational achievement, according to a study funded by the National Institute of Child Health and Human Development (NICHD). The researchers also found that, as adults, the VLBW infants were less likely than their peers to engage in drug or alcohol use and less likely to become pregnant before age 20.
The study is the largest, most comprehensive followup to date of the first group of very low birth weight infants whose survival was made possible by the advances in newborn care technology that began in the late 1970s.
"These results underscore the importance of the NICHD research quest to find the causes of and means to prevent preterm labor," said Duane Alexander, M.D., Director of the NICHD. "Although we don't have all the answers yet, it's encouraging that these adults are doing better in some respects than their counterparts. It's very probable that their avoidance of risky behaviors is due to more attentive parenting. Other NICHD research has shown that children whose parents are actively involved in their lives are less likely to engage in risky behaviors than children whose parents are less involved."
The research was conducted by Maureen Hack, M.B., Ch.B., of the Department of Pediatrics in Case Western Reserve University in Cleveland, Ohio and her colleagues at Cleveland State University and Kent State University. Their findings appear in the January 17 New England Journal of Medicine.
The researchers followed 242 VLBW infants born between 1977 and 1979 until they were 20 years of age. The children weighed an average of 1179 grams (slightly more than 2 ½ lbs.), and were born, on average, during the 29th week of pregnancy. By comparison, a pregnancy is considered full term at 37 weeks.
The researchers found that fewer VLBW young adults had graduated from high school compared a similar group of normal birth weight adults from the same population-74 percent, versus 83 percent. VLBW adults also had lower I.Q. scores than their normal birth weight peers (on average, 87 versus 92). However, the VLBW adults reported less alcohol and drug use than did the normal birth weight adults, and lower rates of pregnancy.
"?we postulate that the more limited risk-taking behavior that we have documented may result from increased parental monitoring of very-low-birth-weight children," the authors wrote.
The NICHD is part of the National Institutes of Health, the biomedical research arm of the Federal government. The Institute sponsors research on development before and after birth; maternal, child, and family health; reproductive biology and population issues; and medical rehabilitation. NICHD publications, as well as information about the Institute, are available from the NICHD website, http://www.nichd.nih.gov, or from the NICHD Information Resource Center, 1-800-370-2943; E-mail NICHDInformationResourceCenter@mail.nih.gov.