Babies Born Very Small Are Likely to Have Problems Later
June 22, 2000 -- Premature babies who are very small at birth run an
increased risk of developmental problems that can be detected as early as 18
months of age, according to a study in the journal Pediatrics. Experts
believe these problems will become more common as medical advances allow the
survival of infants born more than three months premature and weighing 1 pound,
or even less, at birth.
Study author Betty Vohr, MD, and her colleagues studied the conditions at
18-22 months of more than 1,100 extremely low birth-weight children (defined as
babies weighing about 1 to 2 pounds at birth) delivered at 12 hospitals around
the U.S. in 1993 and 1994. They evaluated the babies' development, mental
functions, and medical and social histories. According to Vohr, the tiniest
baby weighed only 14 ounces at birth.
In an interview with WebMD, Vohr stresses that the children's scores in
these areas were evaluated on an age-adjusted basis. For example, she says,
"a child born at 28 weeks might have a chronological age of 6 months, but a
developmental age of only 3 months." This is important because, in such a
child, certain developmental milestones can continue to occur after birth --
just as if the baby had remained in the womb those remaining three months.
Overall, development was normal in over half of these children by age 18 to
22 months. Seventeen percent of the children had cerebral palsy, 11% had some
form of hearing impairment, and 9% had vision problems. The lower a child's
birth weight was, the greater the risk of visual impairment or neurological
Children who had steroid therapy for chronic lung disease immediately after
birth seemed to have the most severe problems, perhaps because they were the
sickest infants. It's not known how steroids may have produced this effect, but
the researchers point out that steroids may have a toxic effect on the brain.
Vohr tells WebMD that the use of neonatal steroids is now being
The researchers also point out that having a higher socioeconomic status may
blunt some of the worst effects of being born so early. Factors such as the
mothers' education level and race were strongly associated with their
children's scores on tests of mental development at 18-22 months of age.
These findings suggest that "higher maternal education is
protective," Vohr says, and that "families with more socioeconomic
problems are at higher risk of having a premature child with developmental
problems." Vohr is director of neonatal follow-up at Women's and Infants
Hospital and professor of pediatrics at Brown University, in Providence,
"This study is a useful addition to the literature," says Stephen
Bates, MD, who reviewed the report for WebMD. The fact that so many premature
children are surviving "is a reflection of excellent perinatal care and
incredibly expensive neonatal care. ... But it raises ethical issues. ? These
children are going to have a huge number of problems."