Human milk is the safest and best source of nutrition for neonates. Due to the high nutrition demands for growth and brain development in the postnatal period, addition of macro- and micronutrients to human milk with fortifiers is needed. It is standard of practice to use human milk fortifiers to create higher calorie levels estimating from 22-30 calories per ounce.
Human milk varies in its macronutrient composition. Some lactating individuals may produce milk that is less than 20 calories per ounce, while others may produce milk that is much higher. Additionally, the composition of the milk one person pumps can vary throughout a 24-hour period and day-to-day.
Target fortification is a newer nutrition practice that aims to reduce variations by measuring individual nutrients and then adding any nutrients to human milk as needed to achieve goal levels. Target fortification may allow maintenance of protein intake and protein:energy ratio to meet recommendations to reduce the risk of over- and undernutrition.1 Additionally, studies evaluating growth are finding that infants may gain more fat-free mass however more research is needed to determine if weight gain is positively impacted.2
Standard Fortification vs Target Fortification
Nutrition practices vary amongst hospitals when it comes to feeding neonates and infants. Majority of centers continue to practice standard fortification of human milk. This involves assuming a fixed calorie per ounce and macronutrient amount in human milk (ex. 20 calorie per ounce, 0.9 gram protein per 100 mL, 8 gram carbohydrates per 100 mL, 3.5 gram fat per 100 mL). From here, human milk fortifiers are added to achieve the goal concentration for feedings. Modulars may be added as well if assuming the baby has higher needs for fat, protein, and/or carbohydrates due to their medical diagnoses and nutritional status. The final product has an estimated nutritional level.
Target fortification starts by taking human milk and analyzing its nutritional components with a milk analyzer. Results show amounts of carbohydrates, protein, and fat in that sample. From here, a fixed dose of fortifier is added to the human milk. After this, modular products (protein, fat, carbohydrates) are added as needed to achieve target nutrient levels. The final product of target fortification has a measured and known nutritional level.
While target fortification appears promising, feasibility can be challenging. First off, a milk analyzer is required and may be cost prohibitive in some settings. Additional materials include syringes, scales, and mixing supplies. Development of protocols for testing milk and adding in fortifiers and modulars to reach appropriate targets is needed. Most importantly, having staff that is trained to properly test milk and implement the nutrition protocols safely is key to success. The added labor of testing human milk samples, calculating changes, and additional steps in milk prep also need to be accounted for.
Milk analysis along with use of modulars allow exact nutrition to be given to high-risk infants. Modulars do, however, have their own nuances. Choosing which specific type of modulars to use that promote tolerance may be challenging due to access, price, osmotic load, and appropriateness of use. Modulars are often powder-based and multi-use which may increase the risk of bacterial contamination. Safe handling along with a sterile area to prepare milk is crucial. Target fortification with modulars includes adding more steps to the milk preparation process and may increase the risk of error. Having streamlined processes with double checks to prevent error will help to ensure the target fortified milk is accurate and safe for baby to consume.
The ability to provide precise nutrition to the most nutritionally at-risk infants is novel and exciting. Considerations including best practices, implementation, feasibility, and safety are areas for research to continue exploring.
- de Halleux V, Rigo J. Variability in human milk composition: benefit of individualized fortification in very-low-birth-weight infants. Am J Clin Nutr. 2013 Aug;98(2):529S-35S. doi: 10.3945/ajcn.112.042689. Epub 2013 Jul 3. PMID: 23824725.
- Parat S, Raza P, Kamleh M, Super D, Groh-Wargo S. Targeted Breast Milk Fortification for Very Low Birth Weight (VLBW) Infants: Nutritional Intake, Growth Outcome and Body Composition. Nutrients. 2020 Apr 21;12(4):1156. doi: 10.3390/nu12041156. PMID: 32326177; PMCID: PMC7230830.