Drops of milk could help preterm babies thrive

It should be so simple: how and what to feed preterm babies. After all, arriving into the world early is hardly a rare occurrence. In New Zealand every year, approximately 5000 babies are born before 37 weeks, of which the majority (4000) are what is known as ‘moderate to late preterm’ - born between 32 and 37 weeks. 

That’s an average of 13 a day, ten of which are moderate to late preterm. Internationally, the World Health Organisation estimates the total number of preterm births at 13 million a year. 

Often with preterm births, there are problems with nutrition. The babies might be too young to suckle, for example, or there’s a delay before mum’s milk comes in, says neonatologist clinician and researcher Distinguished Professor Dame Jane Harding from the University of Auckland’s Liggins Institute. 

“It’s an everyday problem; you have to make a judgement on what is the best option to feed a particular baby at a particular time, but there are many different practices. 

“Should this baby be on parenteral nutrition [an intravenous amino acid solution] or do we use intravenous dextrose? Should we use milk supplements [donor breast milk or formula] or should we just wait another day to see if Mum’s milk comes in? Is it helpful to give a baby the smell or taste of milk before they are tube fed?”

A Liggins Institute-led, multi-year randomised study (the DIAMOND Trial)  aims to bring some clarity around best practice when it comes to feeding those moderate to late preterm babies.

And some of the most recent results are surprising – and encouraging, Harding says. 

A paper published this month suggests babies given a drop or two of milk on a gauze pad beside their nose and on their tongue before and during a tube feed do better in their first two years of life in terms of developmental goals than their peers who didn’t get the milk smell or taste.

Of the 425 two-year-olds assessed in the randomised DIAMOND Trial follow up, neurosensory impairments, particularly language delay, were less likely in the taste/smell group (21 percent versus 31 percent).

It’s a surprising finding, Harding says, but an important one. 

“I didn’t think it would show any difference but we checked our results and then checked them again, and the difference was still there. We also found there was a dose effect – a bigger difference in babies with more exposure to smell and taste

.“This is very exciting because this is an easy, cheap intervention and it’s popular with parents because they can do it themselves.”

The DIAMOND Trial began in 2017 and arose from Liggins researchers asking clinicians across Australia and New Zealand what they did in terms of nutrition for preterm babies.

Everyone did something different, Harding says. “If there are many different practices, it means we don’t know which one is best.”

And this matters, Harding says, and not just for the very vulnerable, very early babies, but for the moderate-to-late preterm ones like those in the DIAMOND Trial. 

These babies are more likely to survive than those born earlier, but they have greater risks of experiencing cognitive, language and motor skills problems than their peers born at term.

“Nutritional support is essential to minimise these risks,” Harding and the other Auckland-based researchers found in the original study. The latest findings are published in the Journal of Pediatrics, in a paper about the two-year follow-up.

“Very few evidence-based guidelines are available on the nutritional needs of children born moderate to late preterm, and practices vary widely."

The DIAMOND study tested three different feeding regimes for these babies, with the goal of establishing best practice guidelines.

The three variables were: intravenous amino acids versus intravenous dextrose; milk supplementation versus breast milk only; and giving babies the taste and smell of milk before tube feeds versus not giving it.

The findings on milk smell/taste and developmental delay will form part of new Liggins Institute-led best practice guidelines for the nutrition of preterm babies, guidelines which are out for public consultation until the beginning of June and due to be released in the second half of this year.

Harding says the results show the importance of follow up studies – particularly when it comes to babies, where the first few years of life are so important. 

The DIAMOND babies are now being reviewed at six or seven years old.

To find out more about Liggins Institute research into the power of the right nutrition for preterm babies, come to the next Liggins Public Lecture, on Thursday July 2 at 6pm.

Tiny babies, big questions: the high-stakes science of early nutrition