While supplements won’t resolve all the adversity of preterm birth it could give children a better start.
Giving omega-3 fatty acid supplements to infants born before 29 weeks’ gestation has been found to increase IQ, Australian researchers have found.
Results of the randomised controlled trial, published in the NEJM, show preterm infants who received direct supplementation of docosahexaenoic acid (DHA) scored 3.5 points higher on the IQ scale at age five years, than those in the control group
Lead author Dr Jacqueline Gould, a postdoctoral research fellow at the South Australian Health and Medical Research Institute (SAHMRI), said it was a significant finding.
“Infants that are born this early also have such a high risk of developmental delays and learning disabilities and all sorts of neurological impairments,” she told The Medical Republic.
“An average IQ for an infant born at less than 29 weeks is 10 to 12 points lower than an average IQ for a term born child, so any improvement is promising.
“We’re not expecting DHA to be able to resolve all of the adversity of preterm birth, but it is quite a decent catch up.”
Infants born before 29 weeks’ gestation are deprived of the natural supply of DHA that normally builds up in the brain during the last trimester of pregnancy. The resulting low concentrations of DHA in their brain tissue may contribute to poorer cognitive outcomes, the authors wrote.
This study followed 323 infants born before 29 weeks’ gestation, who were given 60mg of DHA/kg per day via enteral or control tube feeding. They were compared with 333 children in the control group, who received an emulsion with no DHA.
Dr Gould said the DHA was delivered directly to the infant rather than in premature infant formula or breast milk feeds. This was to maximise the effect of the DHA and deliver the entire dose, at a time when infants might not be tolerating feeds.
“It can be almost three weeks before they are tolerating breast milk or formula feeds and by giving it to them directly through a tube, we could made sure they got the full dose that we thought they needed,” she said.
The supplements were also well-tolerated, and adverse events were similar across groups, Dr Gould said.
“We had around 90% compliance which is really high for any kind of nutritional intervention, and we were quite happy to see it was tolerated so well,” she said.
At five years old, children in both groups underwent the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) IQ test.
“On average, those in the DHA group scored 3.5 points higher on the IQ scale than those in the control group,” Dr Gould said.
“These very promising results suggest DHA has the potential to improve cognitive performance when administered via emulsion for infants born before 29 weeks’ gestation.”
She said that while these were exciting findings for these infants, it was important to understand that they only related to babies in that preterm group. And supplementing any infant would not necessarily translate to a child with a higher IQ.
“We suspect that this is the group of infants it is beneficial for, given the fact that they are missing out on the nutrients and DHA that comes across from the placenta in the last trimester of pregnancy,” she told TMR.
“We studied the children at most risk children of missing DHA and having the poorest outcomes.
“It might be that infants that are born later benefit or they might not, we don’t know, because we didn’t study them.”
The study had an unexpected finding when it came to bronchopulmonary dysplasia, a serious lung condition suffered by many preterm babies since their lungs are under-developed when they are born.
“Although there was some preliminary evidence suggesting that DHA might also be beneficial for this lung condition, we found that it slightly increased the rate of bronchopulmonary dysplasia,” Dr Gould said.
She said this finding needed more evidence, especially around the long term-effects, but was definitely a consideration when making decisions about which babies to treat with DHA supplementation.
