By Gene Emery
Some of the intense care given to the smallest premature infants may be a little too intense, suggest two studies.
One showed that light treatment for jaundice may overwhelm the smallest infants while another questions the practice of giving insulin to premature newborns.
Dr. Brenda Morris of the University of Texas Medical School in Houston and colleagues found that babies weighing less than 1kg were slightly more likely to die if they were given early light therapy for rising levels of bilirubin, the compound that can turn the skin yellow but, more dangerously, can cause permanent brain damage.
When the liver is slow to clear bilirubin, which can be toxic if too much accumulates, high-intensity light is used to break down the compound from outside the body.
The study of 1 974 infants, published in the New England Journal of Medicine, found aggressively treating rising bilirubin levels reduces the rate of brain injury in the form of cerebral palsy, blindness, severe hearing loss and poor cognitive development.
Only 26 percent of light-treated babies had brain damage, compared 30 percent for babies whose treatment was delayed until the levels got a bit higher.
But in the smallest babies, weighing 501 to 750 grams, those treated aggressively were 13 percent more likely to die than those who got conservative care.
The increase was not statistically significant, meaning not enough babies died to know whether the pattern is more than a fluke. Nonetheless, Morris said doctors may want to pause before rushing into light therapy.
"Aggressive phototherapy may be preferred for infants with birth weights of 751 to 1 000 grams, because we found significant neurodevelopmental benefits in this subgroup and no evidence that the therapy increased the rate of death or other outcomes at 18 to 22 months," they wrote.
Dr. Rosemary Higgins, a researcher with the Pregnancy and Perinatology Branch at the National Institutes of Health and co-author of the study, said because jaundice "is one of the many medical problems they're facing, you need to look at these babies on an individual basis" to decide what treatment would be best.
The last study of light therapy was done in the 1970s, before advances allowed much smaller babies to survive.
A second team found that early insulin therapy offers little clinical benefit in very-low-birth-weight infants, putting them at risk of dangerous hypoglycemia or low blood sugar.
Their trial of more than 300 babies showed that putting them on continuous insulin from birth raised the risk of death, with nearly 12 percent dying after four weeks, compared to 5,7 percent of infants not given insulin.
"Mortality at 28 days was higher in the early-insulin group than in the control group," Dr. Kathryn Beardsall of Britain's University of Cambridge and colleagues wrote.