Nutrient Enrichment of Human Milk with Human and Bovine Milk-Based Fortifiers for Infants Born <1250 g: 18-Month Neurodevelopment Follow-Up of a Randomized Clinical Trial

Human milk-derived versus bovine milk-derived fortifier use in very low birth weight infants: growth and vitamin D status

Background

Human milk-derived fortifier (HMDF) coupled with human milk feeding in extremely premature infants reduces the adverse outcome risks of early exposure to bovine milk ingredients but may not provide enough nutrients for adequate catch-up growth compared with bovine milk-derived fortifier (BMDF).

Objective

This study aims to compare HMDF and BMDF effects on growth parameters and serum 25-hydroxy vitamin D (25OHD) levels in preterm very low birth weight (VLBW) infants during the first 8 weeks of life.

Methods

We present a retrospective chart review of inpatient VLBW infants with birth weight <1,500 g and gestational age <32 completed weeks who received either their mother's milk or donor breast human milk fortified with HMDF or BMDF for the first 8 weeks. Weight, head circumference, length gain, and 25OHD level were calculated at 4 and 8 weeks of age.

Results

A total of 139 VLBW infants (91 HMDF + 48 BMDF) received fortified human milk without any supplemental premature formula from birth to 4 weeks of age, of whom 44 (37 HMDF + 7 BMDF) continued until 8 weeks of age. There was no statistically significant difference in the growth parameters between the two groups at 4 and 8 weeks of age. Serum 25OHD level in the HMDF group was significantly higher compared with that in the BMDF group at 4 weeks of age despite receiving lower vitamin D supplementation.

Conclusion

Similar gain in growth parameters in HMDF and BMDF groups at 4 and 8 weeks of age was observed, suggesting that HMDF provides adequate nutrients for growth in VLBW infants. A higher 25OHD level in HMDF may suggest better absorption.

Human milk fortification and use of infant formulas to support growth in the neonatal intensive care unit

Newborn infants require adequate nutrition to achieve full potential growth and development. Early life nutrition and health impacts long-term outcomes through adulthood. Human milk is the optimal source of nutrition during the first 6 months of life. However, infants admitted to the neonatal intensive care unit (NICU) often have comorbidities that create more or different nutrition demands than healthy newborns. There are different strategies to meet the nutrition needs of sick newborns, including use of parenteral nutrition, human milk fortifiers (HMFs), and infant formulas. Multinutrient HMFs are frequently used to achieve the higher nutrition demands of preterm infants. They are available in various presentations, such as human milk- or cow milk-derived, liquid or powder, and acidified or nonacidified, each of which has different risks and benefits associated with its use. Infant formulas are available to meet a demand when mother's own milk or donor breast milk is not available or sufficient, and there are also specialty formulas for infants with certain diseases that present unique nutrition needs. This review is focused on the use of HMFs to support the unique nutrition requirements of preterm infants for healthy growth, as well as the indications for the use of formulas among infants in the NICU.

Use of human milk and fortification in the NICU

Human milk is the gold standard to provide nutritional support for all healthy and sick newborn infants including the very low birth weight (VLBW) infant (<1500 g). It has both nutritional and anti-infective properties which are especially important for these infants at risk for sepsis and necrotizing enterocolitis. Human milk alone is insufficient to meet the nutritional needs for VLBW infants, especially protein and minerals. There is a conundrum between achieving the nutritional, immunologic, developmental, psychological, social, and economic benefit with human milk vs. the inadequate growth with unfortified human milk for VLBW leading to nutritional inadequacy, growth failure and poor neurodevelopmental outcome. The use of multicomponent fortifiers to increase calories and provide additional protein, vitamins, and minerals has been associated with short-term benefits in growth. Most current fortifiers are derived from cow's milk, however there are concerns regarding a possible association between the use of cow's milk-based fortifier and NEC. There is also an exclusive human milk diet with a fortifier derived solely from human milk. There are three approaches for fortifying human milk and include fixed dosage or "blind fortification", adjustable fortification using the blood urea nitrogen as a surrogate for protein nutriture to modify dosage of fortification, and targeted, individualized fortification that is based on periodic human milk analysis.

State of the evidence from clinical trials on human milk fortification for preterm infants

Infants born preterm or low birth weight are at risk for morbidity, mortality and later neuroimpairment. Appropriate early post-natal growth is associated with better outcomes in-hospital and post-discharge. Therefore, nutritional strategies that support growth may improve the long-term health of this population. Mother's milk with donor milk as a supplement are preferred sources of nutrition for these infants but may not always support growth, especially amongst infants born of very low birth weight (<1500 g) and or those with a major morbidity. Systematic reviews of randomised controlled trials to date demonstrate that multi-nutrient fortification of human milk improves in-hospital growth of preterm infants although data on long-term neurodevelopment are lacking. Further, individualised approaches to fortification based on milk analysis or the infant's metabolic response may improve growth over standard fortification. The evidence is insufficient to inform the timing of introducing fortifier, routine fortification of feeds post-discharge or routine use of fortifiers made from human instead of bovine milk. Importantly, there is insufficient data to determine if these fortification practices improve relevant clinical or neurodevelopmental outcomes. In sum, there is an urgent need for well-designed clinical trials to assess potential benefits and risks of fortification practices and at what cost.

Docosahexaenoic acid and arachidonic acid levels are correlated in human milk: Implications for new European infant formula regulations

From February 2022, all infant formula sold in the European Union must contain docosahexaenoic acid (DHA) at ~0.33%-1.14% of total fat with no minimum requirement for arachidonic acid (ARA). This work examines the association between DHA and ARA levels in human milk, the gold standard for infant feeding. Human milk (n = 470) was collected over 12-weeks postpartum from lactating mothers (n = 100) of infants born weighing <1250 g (NCT02137473). Fatty acids were analyzed by gas chromatography. ARA and DHA concentrations were associated in human milk (β = 0.47 [95% confidence interval 0.38-0.56] mol%), including transitional and mature milk, but not colostrum. This remained significant upon adjustment for percentages of other saturated, monounsaturated, n-3, or n-6 fatty acids, day of sample collection, or maternal characteristics (body mass index, ethnicity, education, and income). Infant formulas containing relatively high concentrations of DHA without ARA, as permitted by the new regulations, would not reflect the balance of these fatty acids in human milk.

Neurodevelopmental outcomes of extremely preterm infants fed an exclusive human milk-based diet versus a mixed human milk + bovine milk-based diet: a multi-center study

OBJECTIVE

The objective of this multi-center study was to compare, in infants ≤1250 g birth weight (BW) with neurodevelopmental assessment at 18-22 months of corrected age (CA), whether their neurodevelopmental outcomes differed based on exposure to an exclusive human milk-based (HUM) or to a bovine milk-based fortifier and/or preterm formula (BOV).

STUDY DESIGN

Retrospective multi-center cohort study of infants undergoing neurodevelopmental assessment as to whether HUM or BOV exposure related to differences in outcomes of infants at 18-22 months CA, using the Bayley Scales of Infant Development III (BSID-III). BSID-III cognitive, language, and motor scores were adjusted for BW, sex, study site, and necrotizing enterocolitis.

RESULTS

252 infants from 6 centers were included. BSID-III cognitive scores were higher in the HUM group (96.5 ± 15.1 vs 89.6 ± 14.1, adjusted p = 0.0001). Mean BSID-III language scores were 85.5 ± 15.0 in HUM and 82.2 ± 14.1 in BOV (adjusted p = 0.09). Mean BSID-III motor scores were 92.9 ± 11.7 in HUM and 91.4 ± 14.6 in BOV (adjusted p = 0.32).

CONCLUSION

In this cohort of infants undergoing neurodevelopmental assessment, infants receiving HUM diet had significantly higher cognitive BSID-III scores at 18-22 months CA. Further investigation is needed of this potential for HUM to positively influence infant cognitive outcomes.

Using Nature to Nurture: Breast Milk Analysis and Fortification to Improve Growth and Neurodevelopmental Outcomes in Preterm Infants

Premature infants are born prior to a critical window of rapid placental nutrient transfer and fetal growth-particularly brain development-that occurs during the third trimester of pregnancy. Subsequently, a large proportion of preterm neonates experience extrauterine growth failure and associated neurodevelopmental impairments. Human milk (maternal or donor breast milk) is the recommended source of enteral nutrition for preterm infants, but requires additional fortification of macronutrient, micronutrient, and energy content to meet the nutritional demands of the preterm infant in attempts at replicating in utero nutrient accretion and growth rates. Traditional standardized fortification practices that add a fixed amount of multicomponent fortifier based on assumed breast milk composition do not take into account the considerable variations in breast milk content or individual neonatal metabolism. Emerging methods of individualized fortification-including targeted and adjusted fortification-show promise in improving postnatal growth and neurodevelopmental outcomes in preterm infants.

Evidence summary of human milk fortifier in preterm infants

BACKGROUND

To search for and collect evidence on human milk fortifier in preterm infants, and to summarize the latest and best evidence, so as to provide reference for clinical work.

METHODS

We searched the databases of UpToDate, American Guide Network, Cochrane Library, Joanna Briggs Institute (JBI), PubMed, ResearchGate, China National Knowledge Infrastructure (CNKI), Wan Fang, Chinese Biology Medicine disc (CBM), and Yi Maitong, and collected relevant guidelines, systematic reviews, evidence summaries, expert consensuses, and randomized controlled trials (RCTs). The retrieval time limit was from the database establishment to July 2021. The quality of the literature was independently evaluated by 2 researchers, who then extracted and summarized the evidence from qualifying articles.

RESULTS

A total of 16 articles were selected, including 3 guidelines, 3 systematic reviews, 5 expert consensuses, 3 RCTs, and 1 best practice guideline, including indications, time for usage, methods, monitoring and management, time of cessation, health education, and post-discharge feeding.

CONCLUSIONS

This study summarized the best evidence for human milk fortifier in preterm infants. Medical staff should assess the specific clinical conditions and parental wishes when applying the best evidence to ensure the effectiveness and safety of human milk fortifier, thus improving the quality of clinical nursing.

Growth, Body Composition, and Neurodevelopmental Outcomes at 2 Years Among Preterm Infants Fed an Exclusive Human Milk Diet in the Neonatal Intensive Care Unit: A Pilot Study

Background: Long-term outcomes of preterm infants fed an exclusive human milk-based (EHM) diet using a donor human milk-based fortifier are not well defined. Materials and Methods: Infants ≤1,250 g birth weight (BW) were studied prospectively at two outpatient visits: 12-15 and 18-22 months corrected age (CA). Dual-energy X-ray absorptiometry and Bayley Scales of Infant and Toddler Development III (BSID-III) were performed at 18-22 months CA. Results: In this pilot study, 51 preterm infants (gestational age 27.8 ± 2.6 weeks and BW 893 ± 204 g) were evaluated. While anthropometric z-scores were significantly lower at discharge compared with birth, z-scores returned to birth levels by 12-15 months CA (length and head circumference [HC]) and 18-22 months CA (weight). Body composition at 2 years of age was similar to term-matched controls. Inpatient growth was significantly correlated with bone density, lean mass (LM), and fat-free mass at 18-22 months CA. Increased mother's own milk (MOM) was significantly correlated with decreased fat mass indices. BSID-III showed that 0% of cognitive composite scores were <70. Conclusions: In addition to returning to BW, length, and HC z-scores by 2 years of age, body composition analysis revealed that increase in body size was appropriate as reflected by LM and bone density similar to matched term controls without an increase in fat mass. No child had severe cognitive developmental delay using a cutoff score of 70. Inpatient growth and increased receipt of MOM correlated with favorable growth and body composition outcomes. Positive outcomes as shown in this study to confirm postdischarge safety of an EHM diet during hospitalization.