Overview
Definition:
Human milk fortification involves adding specific nutrients to expressed human milk to meet the increased nutritional demands of preterm or low birth weight infants who cannot be adequately nourished by unfortmified milk alone
Standard fortification uses a fixed formula to add micronutrients and macronutrients, while targeted fortification customizes the fortification based on individual infant needs and laboratory assessments.
Epidemiology:
Prevalence of preterm birth varies globally, with significant numbers of low birth weight infants requiring specialized nutritional support
In India, rates of preterm births and low birth weight infants necessitate effective feeding strategies, making fortification crucial
Approximately 10-15% of all births are preterm, with a substantial proportion requiring NICU admission and fortification.
Clinical Significance:
Adequate nutrition is paramount for the growth and development of vulnerable infants, particularly those born prematurely
Human milk is the gold standard, but unfortified milk often lacks sufficient calories, protein, vitamins, and minerals to support rapid catch-up growth and prevent nutrient deficiencies
Fortification aims to prevent malnutrition-related morbidities such as rickets, osteopenia of prematurity, anemia, and impaired neurodevelopment, thereby improving long-term outcomes and reducing healthcare costs
Understanding the nuances between standard and targeted approaches is critical for optimizing care and is a frequent topic in DNB and NEET SS examinations.
Standard Fortification
Description:
Standard fortification involves adding a universal fortifier to all expressed human milk feeds
This fortifier typically contains a fixed amount of protein, carbohydrates, fats, vitamins (including vitamin D, A, E, K, C, B vitamins), and minerals (including calcium, phosphorus, iron, zinc, selenium).
Common Fortifiers:
Commercially available multi-nutrient fortifiers are commonly used
These are designed to meet the general nutritional requirements of most preterm infants
Examples include formulas providing approximately 24-30 kcal/oz and specific micronutrient levels per volume of milk.
Administration:
The fortifier is mixed with expressed human milk according to manufacturer guidelines or institutional protocols, typically just before feeding to ensure nutrient stability
The final caloric and nutrient density is calculated based on the volume of milk and the amount of fortifier added.
Advantages:
Simplicity in preparation and administration
Reduces the risk of severe nutrient deficiencies by providing a consistent nutritional profile
Less labor-intensive for nursing staff
Widely accepted and implemented in many NICUs.
Disadvantages:
Does not account for individual infant variations in nutrient absorption, intake, or growth
May lead to over- or under-fortification in some infants
Requires regular monitoring for signs of deficiency or toxicity, though less frequent than in targeted approaches.
Targeted Fortification
Description:
Targeted fortification is an individualized approach where the type and amount of fortifier are adjusted based on the infant's specific clinical status, growth trajectory, and biochemical markers.
Assessment Parameters:
Key parameters include birth weight, gestational age, postnatal age, caloric intake, growth velocity (weight, length, head circumference), serum electrolytes, calcium, phosphorus, alkaline phosphatase, albumin, hemoglobin, and vitamin levels
Monitoring for signs of rickets or osteopenia is crucial.
Customization:
If an infant shows poor growth, low serum calcium/phosphorus, or high alkaline phosphatase, the fortification may be increased, particularly with calcium, phosphorus, and vitamin D
Conversely, if an infant has evidence of electrolyte imbalance or other issues, the fortification may be adjusted or supplemented differently.
Benefits:
Provides precise nutritional support tailored to individual needs, potentially leading to better growth and reduced risk of specific nutrient deficiencies or excesses
Can optimize outcomes for very preterm infants with complex nutritional challenges.
Challenges:
Requires intensive monitoring and laboratory assessments, increasing healthcare costs and workload
Can be complex to manage and requires skilled personnel for accurate interpretation of data and adjustment of feeds
Risk of errors in calculation or administration
Limited evidence base for all specific customization strategies.
Nutritional Components And Targets
Energy:
Targets are typically 110-135 kcal/kg/day for catch-up growth in preterm infants
Standard fortifiers aim to achieve this density when combined with human milk.
Protein:
Requirements are high, around 3.5-4.5 g/kg/day
Fortifiers usually add sufficient protein to reach these targets.
Calcium And Phosphorus:
Essential for bone mineralization
Targets are often 100-200 mg/kg/day for calcium and 50-120 mg/kg/day for phosphorus
Ratios are critical, often aiming for 1.5-2:1 Ca:P
Serum levels and alkaline phosphatase are key monitoring parameters.
Vitamins:
Vitamin D (400-800 IU/day), Vitamin A, E, K, C, and B vitamins are added
Specific needs may vary, and monitoring for deficiencies like ROP (Vitamin E) or anemia (folate, B12) is important.
Minerals:
Iron (2-4 mg/kg/day) is crucial to prevent anemia
Zinc and selenium are also added
Levels are monitored based on clinical status and laboratory tests.
Diagnostic Approach To Deficiencies
History And Physical Exam:
Inquire about feeding history, growth patterns, and any signs of bone disease (e.g., frontal bossing, metaphyseal fraying), anemia (pallor, fatigue), or neurological deficits
Physical exam should assess growth parameters, bone structure, and signs of dehydration or malabsorption.
Laboratory Investigations:
Key tests include serum calcium, phosphorus, magnesium, alkaline phosphatase (especially 5' nucleotidase), albumin, complete blood count (hemoglobin, hematocrit), iron studies (ferritin, transferrin saturation), and vitamin levels (e.g., Vitamin D, Vitamin E) if deficiency is suspected.
Imaging:
Radiographs of long bones can reveal rickets (widened, cupped metaphyses, osteopenia)
Bone mineral density studies (e.g., DXA scan) can be used in specific cases to assess osteopenia of prematurity.
Interpretation:
Low calcium/phosphorus with elevated alkaline phosphatase strongly suggests osteopenia of prematurity
Anemia workup guides iron or vitamin supplementation
Growth charts are essential for tracking progress and identifying faltering.
Management Of Fortification Issues
Medical Management:
If standard fortification leads to deficiencies, adjustment of the fortifier or additional supplementation (e.g., parenteral calcium/phosphorus, vitamin D, iron, specific amino acids) may be required
For very low birth weight infants, parenteral nutrition may be used adjunctively
Specific drug examples: Calcium gluconate, phosphate supplements, ferrous sulfate, ergocalciferol.
Supportive Care:
Close monitoring of fluid balance, electrolytes, and metabolic status is critical
Regular follow-up of growth parameters and nutritional markers is essential
Breast milk or donor milk remains the preferred base
Enteral feeding intolerance may necessitate adjustments or temporary parenteral support.
Prevention Strategies:
Implementing a robust standard fortification protocol from the outset for appropriate infants is the first step
For infants at higher risk, a transition to targeted fortification, guided by serial assessments, can prevent deficiencies
Educating nursing and medical staff on proper preparation and administration is paramount.
Key Points
Exam Focus:
DNB and NEET SS examine the principles of neonatal nutrition, understanding the rationale behind human milk fortification, recognizing signs of nutrient deficiencies, and knowing the differences between standard and targeted approaches
Specific nutrient targets for preterm infants are frequently tested.
Clinical Pearls:
Always check the fortification details on the milk container
When in doubt about an infant's nutritional status, review their intake and growth trajectory
a deficit here often points to a fortification issue
Remember to consider the Ca:P ratio in bone health
The goal is adequate but not excessive fortification.
Common Mistakes:
Failing to fortify human milk for appropriate preterm infants
Incorrect calculation of fortification volumes
Over-reliance on one method without considering individual infant needs
Not monitoring for complications like hypercalcemia or electrolyte imbalances
Delaying iron supplementation.