Effects of Implementation of a Care Bundle on Rates of Necrotising Enterocolitis and Own Mother's Milk Feeding in the East Midlands: a Mixed Methods Impact and Process Evaluation Study

Necrotising enterocolitis (NEC) is a serious, life-threatening disease in preterm infants. Preterm birth, affecting over 52,000 babies per year (around 7.3% of live births), is the largest cause of neonatal mortality in the UK. The 2019 NHS Long Term Plan aims to reduce neonatal mortality by 50% with plans to "improve the safety and effectiveness of neonatal critical care" and "enhance the experiences of families" during this worrying period.

An estimated 12% of infants born weighing <1500g develop NEC and 30% of these die. Survivors have an increased risk of adverse neurodevelopmental outcomes, including cerebral palsy and cognitive impairment. In the UK, NEC rates are collected by the National Neonatal Audit Programme (NNAP), a national audit run by the Royal College of Paediatrics and Child Health, commissioned by the Healthcare Quality Improvement Partnership (https://nnap.rcpch.ac.uk).

The East Midlands Neonatal Operational Delivery Network (EMNODN) (https://www.emnodn.nhs.uk) is one of 11 clinically managed Neonatal Operational Delivery Networks in England. ODNs were formed, in 2003, by the Department of Health, to ensure that babies and their families receive high quality, equitable and accessible care. The rate of NEC in the EMNODN has remained above the national average since 2017 (when this measure was added to NNAP) and there are wide variations between units.

Preterm infants are unable to directly suckle on the breast. Mothers express breastmilk which is fed to their infant via an oro/nasogastric tube. As infants grow and mature, they develop the ability to suck and swallow and establish breastfeeding. Some infants continue to receive own mother's milk via a cup, syringe, or bottle as per parental choice; all these are included within 'own mother's milk feeding'. Encouraging and supporting own mother's milk feeding prevents NEC and has several additional advantages, including improved long-term neurodevelopment and parent-infant bonding. Health economic analysis estimates that if all premature infants were fed own mother's milk, the total lifetime cost saving to the NHS would be £46.7 million (£30.1 million in the first year of life) and there would be 238 fewer deaths per year with a gain of £153.4 million in lifetime productivity. The adjusted incremental costs of medical NEC and surgical NEC over and above the average costs incurred for extremely premature infants without NEC, in 2011, were estimated to be $74,004 (95% confidence interval (CI), $47,051-$100,957) and $198,040 (95% CI, $159,261-$236,819) per infant, respectively.

Early start and continuation of feeding with own mother's milk, such that babies go home breastfeeding, is vital to ensure babies continue to receive own mother's milk throughout neonatal care and remain at a reduced risk of NEC. Unfortunately, in NNAP, rates of any breast milk feeding at discharge in EMNODN have been consistently below the national average, again with wide local variations.