With an increasing body of evidence to support a causal link between drinking milk that contain cow's milk protein (CMP) and the development of gastrointestinal disturbance in infants, many clinicians avoid the use of CMP containing feed in high risk babies.

Delivery of adequate nutritional intake is one of the great challenges in the care of newborn infants, particularly those born preterm or with gastrointestinal problems. Whilst there are recognised benefits of human milk, a diet of exclusive human milk may not meet the nutritional demands of the infant. To close this gap, breast milk fortifier (BMF) is typically added to human milk. However, addition of BMF may be associated with gastrointestinal disturbance, possibly due to the fact that it contains CMP.

This research study is to test the tolerability and safety of a new human milk-based BMF in neonates with gastrointestinal problems. It is hoped that this may provide an opportunity for high risk infants, to receive the benefits of human milk whilst minimising the risks reported to be associated with CMP.

Eligible infants will be those in whom nutritional supplementation of breast is deemed clinically necessary, a weight of greater than 1.0kg at the time of starting fortifier and at least one of:

• previous gastrointestinal surgery
• congenital gastrointestinal anomaly
• medically treated gastrointestinal disease
• previously suspected intolerance of CMP based breast milk fortifier in the absence of other gastrointestinal disease

Infants will be started on human milk-based BMF once they are tolerating 100 mls per kilo per day of human breast milk. The human milk-based fortifier will be commenced at half the recommended dose for 48 hours then increase to full strength. This will be continued until the infant reaches 44 weeks corrected gestational age, or until such time as they are deemed to no longer require the additional nutrition.

BACKGROUND There is an increasing body of evidence to support a causal link between ingestion of cow's milk protein (CMP) containing milks and the development of gastrointestinal disturbance in preterm and term infants. In particular the development of necrotising enterocolitis (NEC) has been associated with use of CMP containing feed in both epidemiological studies and a small number of prospective trials. It may be that this is due to a lack of the protective effect of breast milk, rather than CMP pe se. In addition to NEC, CMP containing feed may be implicated in the development of other gastrointestinal disturbance in preterm infants and as such many clinicians avoid the use of CMP containing feed in high risk infants. One such group are preterm infants who have already had an episode of NEC. Others include those born with a congenital anomaly of the gastrointestinal tract such as gastroschisis.

One of the great challenges in the care of the preterm neonate is the delivery of adequate nutritional intake to support growth and development. Whilst there are recognised benefits of human milk for preterm infants, a diet of exclusive human milk does not meet the nutritional and metabolic demands of the preterm infant(4). To close this nutritional gap, breast milk fortifier (BMF) is typically added to human milk. BMF is manufactured from cow's milk, and so contains hydrolysed CMP. However, there is concern that this addition of BMF may be associated with gastrointestinal disturbance, and this may be due to the fact that it contains elements of CMP. In view of this potential association, there is an understandable reluctance to use standard BMF in infants who have already had evidence of gastrointestinal disturbance, such as NEC or gastrointestinal surgery.

RATIONALE Recently a human milk based breast milk fortifier (NeoKare) has become available and is currently being evaluated in the preterm population when compared to current standard feeding practice. Provision of such an exclusive human milk diet may not carry the same risk of gastrointestinal disturbance and may represent an opportunity for high-risk preterm infants that have had NEC, undergone gastrointestinal surgery or had other gastrointestinal disturbance felt to be related to type of milk, to receive the benefits of human milk together with the nutritional benefits of milk fortification, whilst minimising the risks reported to be associated with exposure to CMP. Being able to improve nutrient intakes in this way using human milk based fortifier, may reduce the need for parenteral nutrition, and in turn reduce the risk of complications of parenteral nutrition, length of stay and hospital costs. To date this human milk-based breast milk fortifier has not been formally evaluated in this group of infants.

There is a need to establish if NeoKare is tolerated by infants with pre-existing gastrointestinal disturbance, and see if it can be safely used in this population. There is also a need to see if it enables better nutrition and growth, and earlier cessation of PN, and in turn a shorter length of stay, These may have cost related benefits, which also need to be explored.

Primary objective The primary aim of the study is to investigate the tolerability of a powdered human milk-based breast milk fortifier (Neokare) in infants cared for on a neonatal unit with pre-existing gastrointestinal disturbance (previous gastrointestinal surgery, medically treated gastrointestinal disease, previously suspected intolerance of cow's milk protein-based breast milk fortifier in the absence of other gastrointestinal disease or a congenital gastrointestinal anomaly not requiring surgery). This will be compared to a retrospective control group of similar infants born prior to the study who were not managed using the NeoKare product

Secondary objectives The main secondary aim of the study is to investigate the safety of a powdered human milk-based breast milk fortifier (Neokare) in infants cared for on a neonatal unit with pre-existing gastrointestinal disturbance (previous gastrointestinal surgery, medically treated gastrointestinal disease, previously suspected intolerance of cow's milk protein-based breast milk fortifier in the absence of other gastrointestinal disease or a congenital gastrointestinal anomaly not requiring surgery) This will be compared to a retrospective control group of similar infants born prior to the study who were not managed using the NeoKare product Other secondary aims of the study are to see if, in infants cared for on a neonatal unit with pre-existing gastrointestinal disturbance (previous gastrointestinal surgery, medically treated gastrointestinal disease, previously suspected intolerance of cow's milk protein-based breast milk fortifier in the absence of other gastrointestinal disease or a congenital gastrointestinal anomaly not requiring surgery), the use of a powdered human milk-based breast milk fortifier (Neokare) leads to improvements in growth, nutrition, length of stay, time on parenteral nutrition and other clinical outcomes compared to a retrospective control group of similar infants born prior to the study who were not managed using the NeoKare product. Cost of care will also be compared.

TRIAL DESIGN This will be a Prospective observational cohort study with a retrospective control group

Inclusion Criteria:

All of the following must be met:

1. Current weight greater than ≥ 1.5kg (this will reduce to current weight of ≥ 1.0kg following midpoint review if no safety concerns

2. Deemed by attending clinician that fortification of breast milk is desirable either to meet nutritional requirements or optimise growth

3. Exclusive maternal or donor breast milk feeding (at time of starting fortifier)

4. At least one of the following diagnostic criteria:

   1. Any previous gastrointestinal tract surgery. This may include but is not limited:

      • Surgery for NEC
      • Gastroschisis
      • Spontaneous Intestinal Perforation
      • Intestinal Atresias and Webs
      • Malrotation
      • Hirschsprung's disease
      • Volvulus
      • Exomphalos
      • Meconium Ileus/plugs
      • Anorectal anomalies

   2. Medically treated gastrointestinal disease including but not limited to necrotising enterocolitis (based on nationally agreed case definitions), meconium ileus of prematurity (clinical diagnosis), milk curd obstruction (clinical diagnosis)

   3. Previously suspected intolerance of cow's milk protein-based breast milk fortifier in the absence of other gastrointestinal disease (clinical diagnosis)

   4. Congenital gastrointestinal anomaly (not requiring surgery)

Exclusion Criteria:

Any of the following will result in exclusion:

1. Known congenital metabolic disorder
2. Formula fed prior to diagnosis being made
3. Bilateral grade III or IV intra-ventricular haemorrhage
4. Any infant who has had gastrointestinal tract surgery and received feed other than breast milk following surgery and prior to commencing the study
5. Refusal of consent, refusal for the use of pasteurised donor human milk

The reason for these exclusion criteria is to exclude any baby in whom the primary outcome may be adversely influenced by co-existing medical morbidities

The aim of these inclusion criteria is to select a group of babies typically requiring nutritional supplementation of breast milk but in whom there is currently a reluctance to provide cow's milk-based breastmilk fortifiers.