Preemies given extra nutrition grew faster but got more infections

Extremely premature babies who weigh less than 1.5 kg at birth have an increased risk of having lower IQs and learning difficulties later in life. Nutrition is a key factor in helping avoid these problems.

But premature babies often grow poorly. Many weigh less than might be expected when they are discharged from the hospital.

One reason behind this may be that they get too little nutrition as newborns.

Six per cent of all babies born in Norway each year are born prematurely, but only 400 are considered extremely premature. An extremely premature birth is when babies are born between 22 and 27 weeks of pregnancy.

Breast milk and added nutrition

Now, medical doctor and researcher Elin Wahl Blakstad at Akershus University Hospital (A-hus) has investigated what happens when premature children who weigh very little are given extra nutrition.

The 50 children who participated in the study were divided into two groups. One group was fed according to applicable nutritional guidelines. The other group received more energy, protein, fat, fatty acids and vitamin A than is normally recommended.

“According to current guidelines, babies should receive intravenous nutrition at the start, as well as breast milk with a little enrichment. We gave more intravenous nutrition and added extra enrichment to the mother's milk in one group,” Blakstad said.

Additional nutrition boosted growth

The results showed that children who received more protein and fat than recommended grew better than those who only received nutrition according to the guidelines.

These children also had more stable weight gain and better head growth while they were in the hospital than the babies who didn’t get the augmented nutrition.

“They grew significantly better, particularly right after birth. Ordinarily, it is common for these babies to lose weight due to fluid loss during the first few days after they are born,” Blakstad said.

Weight gain can have a positive effect on brain development in premature babies.

The children who weren’t given nutrition above and beyond the guidelines had poorer growth during their hospital stay, but grew more after they were discharged. Premature babies may be sent home around their actual due date or a few weeks before, depending on their health status.

Increased visual response

Other studies have also shown that children who received more nutrition were more responsive to movement when they were visually stimulated.

The children with the best weight gain also had a healthier intestinal bacterial flora.

The researchers concluded that optimized nutrition for premature infants with very low birth weight allows for better growth and can be important for brain development.

Norwegian hospitals follow both international and Norwegian guidelines for how much nutrition premature children should be given.

"These international guidelines are constantly being revised, so these studies may have some impact on how much extra nutrition we will give these babies," says Blakstad.

Got more infections

But the study was stopped earlier than planned because the children who received more nutrition also got more frequent infections.

"Measurements showed that these children had an increased tendency to get infections, based on a finding of bacteria in the blood, but we don’t know why," says Blakstad.

One possible reason is that the babies’ electrolyte levels were out of balance because of the extra nutrition.

"It is possible that these babies need more phosphate because they grow faster," she said.

Blakstad said the findings show that more research is needed on what and how much nutrition is to be added to the diet of these children.

"This is a difficult balancing act, where giving a baby more protein and energy often also requires giving them more minerals," she said.

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Read the Norwegian version of this article at forskning.no