NICU Fortification Approaches: Weighing the Benefits and Challenges

Neonatal Intensive Care Units (NICUs) play a critical role in the care of preterm and sick infants. Fortification of milk is an important nutritional intervention used to promote the growth and development of preterm infants. However, fortification methods offer various advantages and challenges that require careful consideration.

The Importance of Fortification

Preterm infants, particularly those with very low birth weight (<1500 g) and <32 weeks gestation, have higher nutritional requirements to achieve in-utero growth. Human milk (HM) considered as the gold standard, needs fortification with human milk fortifiers (HMFs) to provide additional calories, proteins, vitamins, and minerals.

Choice of HMFs

HMFs are usually derived from bovine milk and they improve growth parameters in the short-term. However, bovine milk-based fortifiers (BMBF) carry a potential risk of feeding intolerance and allergic reactions due to bovinemilk protein. On the other hand, human milk-based fortifiers (HMBF) are better tolerated and are known to reduce the incidence of necrotizing enterocolitis (NEC), retinopathy of prematurity, bronchopulmonary dysplasia, and death. HMBF further boosts the immune factors through the bioactive compounds retained in the HMBFs including Human milk oligosaccharides (HMOs), immunoglobulins, and lactoferrin, which are unique to HM.

Mono-component nutrient fortifiers, such as protein or lipids could help infants achieve the targeted nutrition. As fortifiers are deficient in Vitamin D and iron, they need to be supplemented.

Benefits of Fortification

1. To enhance nutritional content: Fortified HM provides additional macronutrients, micronutrients,and calories that support rapid growth and development of preterms, particularly the brain and other vital organs.

2. Improved growth and bone density: Fortified HM helps preterm infants achieve better weight gain, length, and head circumference in the short term. It also supplements calcium and phosphate required for bone mineralisation.

3. Provides Immune protection: HM contains antibodies and other immune-protective factorsthat help protect infants from infections. Fortification ensures these infants receive the benefits of mother’s milk during the critical phase of their development.

Challenges of Fortification

1. Tolerance Issues: Fortified milk can cause feeding intolerance, vomiting, diarrhea, and necrotizing enterocolitis, hence need close monitoring.

2. Nutritional Variability: Wide variation in the composition of HM complicatesfortification, and over or under-fortification can lead to suboptimal growth. Analysis of HM, though ideal is neither practical nor feasible and is limited to research labs at present.

3. Availability of HM: Ensuring a steady supply of pasteurized donor human milk (PDHM) in the absence of mothers' milk or banked milkcan be challenging.

4. Cost: HMBFs are comparatively costlier than BMBFs. However, therapeutic value should be given priority.

Balancing the Benefits and Challenges

Healthcare providers need to adopt a personalized evidence-based approach, which includes:

1. Individualised Nutritional Plans: Tailoring fortification to address the specific needs of each infantby analysing the HM (targeted fortification).

2. Regular Monitoring and Adjustment: Regular monitoring of growth parameters (anthropometry) and blood urea estimation to adjust fortification (adjustable fortification).

3. Ensuring osmolality of the feed: Fortified milk should have an osmolality of<450 mOsm/Kg to prevent feeding intolerance.

4. Early versus late Fortification: Fortification of HM is started when an infant tolerates 100 ml/kg/day of feeds, but early fortification of HM (40 ml/kg/day) promotes growth and prevents growth faltering.

Overall, HMFs are recommended till preterm reach a weight of 2000 grams or 40 weeks of corrected age, whichever is earlier. Every effort should be made to provide mother’s milkas the first choice of feed and in the absence of mother’s milk, either banked milk or PDHM should be given to maintain an exclusive human milk-based diet for better outcome.