Osmolality of a fortified human preterm milk: The effect of fortifier dosage, gestational age, lactation stage, and hospital practices

Osmolality of fortified donor human milk: An experimental study

BACKGROUND

We quantify the osmolality of human milk fortified with human milk fortifiers (HMFs), powder infant formulas and protein additives.

METHODS

Commercial liquid HMFs and powder infant formulas were added to pasteurized pooled donor human milk in triplicate and stirred. The osmolality of unfortified and fortified human milk at 22, 24, 26, 27, 28, and 30 kcal/oz (0.73, 0.8, 0.87, 0.9, 0.93, and 1 kcal/ml, respectively) was determined using freezing-point depression.

RESULTS

The osmolality of fortified human milk associated with energy density in a linear relationship regardless of the fortification strategies. Multiple liquid HMFs and every powder infant formula exceeded the osmolality threshold of 450 mOsm/kg H2 O within the energy densities tested.

CONCLUSION

The osmolality of fortified human milk is highly variable and should be considered when selecting a fortifying agent for human milk.

Effect of fortification on the osmolality of human milk

BACKGROUND

It is known that human milk fortifiers (HMF) increases osmolality of human milk (HM) but some aspects of fortification have not been deeply investigated. Our aim was to evaluate the effect of fortification on the osmolality of donor human milk (DHM) and mother's own milk (MOM) over 72 h of storage using two commercial fortifiers and medium-chain triglycerides (MCT) supplementation.

METHODS

Pasteurized DHM and unpasteurized preterm MOM were fortified with 4% PreNAN FM85, 4% PreNAN FM85 plus 2% MCT, or 4% Aptamil BMF. Osmolality was measured in unfortified DHM and MOM and, moreover, just after fortification (T₀), and after 6 (T₆), 24 (T₂₄) and 72 h (T₇₂) to determine the effect of mixing and storage.

RESULTS

Unfortified DHM and MOM did not show changes of osmolality. Fortification increased osmolality of DHM and MOM without changes during the study period, except for Aptamil BMF which increased osmolality of MOM. The addition of MCT to fortified human milk (FHM) did not affect its osmolality.

CONCLUSIONS

Changes of osmolality in the 72 h following fortification of both DHM and MOM did not exceed the safety values supporting the theoretically possibility of preparing 72 h volumes of FHM. Supplementation with MCT of FHM does not change osmolality suggesting that increasing energy intake in preterm infants via this approach is safe.

Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition and Invited Experts

OBJECTIVES

To review the current literature and develop consensus conclusions and recommendations on nutrient intakes and nutritional practice in preterm infants with birthweight <1800 g.

METHODS

The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee of Nutrition (CoN) led a process that included CoN members and invited experts. Invited experts with specific expertise were chosen to represent as broad a geographical spread as possible. A list of topics was developed, and individual leads were assigned to topics along with other members, who reviewed the current literature. A single face-to-face meeting was held in February 2020. Provisional conclusions and recommendations were developed between 2020 and 2021, and these were voted on electronically by all members of the working group between 2021 and 2022. Where >90% consensus was not achieved, online discussion meetings were held, along with further voting until agreement was reached.

RESULTS

In general, there is a lack of strong evidence for most nutrients and topics. The summary paper is supported by additional supplementary digital content that provide a fuller explanation of the literature and relevant physiology: introduction and overview; human milk reference data; intakes of water, protein, energy, lipid, carbohydrate, electrolytes, minerals, trace elements, water soluble vitamins, and fat soluble vitamins; feeding mode including mineral enteral feeding, feed advancement, management of gastric residuals, gastric tube placement and bolus or continuous feeding; growth; breastmilk buccal colostrum, donor human milk, and risks of cytomegalovirus infection; hydrolyzed protein and osmolality; supplemental bionutrients; and use of breastmilk fortifier.

CONCLUSIONS

We provide updated ESPGHAN CoN consensus-based conclusions and recommendations on nutrient intakes and nutritional management for preterm infants.

Extremely low birthweight neonates with phenylketonuria require special dietary management

AIM

Extremely low birthweight (ELBW) neonates require a high protein intake, but this can be challenging in the very rare cases when they also have phenylketonuria (PKU). This is due to a lack of suitable parenteral nutrition or enteral formula. Our aim was to analyse tolerance to phenylalanine in these infants.

MATERIAL

There are approximately 110 000 children born in the Czech Republic each year. A neonatal screening programme from 2005 to 2020 found that 320 neonates had PKU, including 30 premature neonates with a birth weight of less than 2500 g.

RESULTS

This study focused on three neonates who were born with ELBWs of 720, 740 and 950 g, respectively. Phenylalanine levels normalised in ELBW neonates with PKU within 1 week of the introduction of low-phenylalanine parenteral or enteral nutrition. The tolerance to phenylalanine was very high (70-110 mg/kg) in the first months of life, due to a rapid weight gain, but significantly decreased during infancy.

CONCLUSION

Extremely low birthweight neonates with PKU need special dietary management. Regular assessments of phenylalanine are necessary during the first weeks of life to allow prompt dietary adjustments that reflect rapid weight gain and transitory high tolerance to phenylalanine.

Corrected fortification approach improves the protein and energy content of preterm human milk compared with standard fixed-dose fortification

OBJECTIVE

To evaluate whether a pragmatic corrected fortification (CF) model achieves recommended target protein and calorie content of human milk (HM) for preterm infants when compared with standard fixed-dose fortification (SF).

DESIGN

In this prospective non-interventional study, we enrolled mothers of infants with birth weight ≤1500 g fed exclusive HM. Infants with chromosomal or intestinal disorders were excluded. A total of 405 HM samples from 29 mothers and 45 donor milk samples were analysed for macronutrient content using a real-time HM analyser. A stepwise CF model was derived based on published data on HM calorie and protein content corrected for lactation stage and milk type. We applied both models to the measured protein and calorie content for all HM samples and compared the proportion of samples achieving target nutrient requirement in each group.

RESULTS

Target protein and calorie content of feed was achieved in 68% of HM samples with CF, compared with 5% samples with SF model (p<0.0001). For mother's own milk, none of the samples met the target macronutrient range with SF fortification during later lactation periods (≥week 5). With SF, over 40% of infants had poor growth (decline in weight z-score ≥0.8 SD) by 8 weeks. The final feed osmolality was acceptable for all fortification steps of the CF model.

CONCLUSION

The proposed CF model significantly improved the final protein and calorie content of HM with acceptable osmolality. It provides a proactive option to improve nutrient intake in premature infants.

Fortifier selection and dosage enables control of breast milk osmolarity

BACKGROUND

Human breast milk (BM) fortification is required to feed preterm newborns with less than 32 weeks of gestation. However, addition of fortifiers increases osmolarity and osmolarity values higher than 450 mOsm/kg may be related to gastrointestinal pathology. Hence, fortifier selection and dosage are key to achieve optimal feeding.

OBJECTIVES

To compare the effect on osmolality of adding different fortifications, including recently developed formulations, to BM and to study evolution of osmolarity over time in supplemented BM.

METHODS

Frozen mature BM from 10 healthy mothers of premature newborns was fortified with each of the following human milk fortifiers (HMF): AlmirónFortifier®, NANFM85®, or PreNANFM85®. In addition, fortified BMs were modified with one of the following nutritional supplements (NS): Duocal MCT®, Nutricia® AminoAcids Mix, or Maxijul®. Osmolality of BM alone, fortified and/or supplemented was measured at 1 and 22 hours after their preparation. All samples were kept at 4°C throughout the study.

RESULTS

Osmolality of BM alone was close to 300 mOsm/kg and did not change over 22 hours. When equicaloric amounts of HMF AlmirónFortifier®, NANFM85®, and PreNANFM85® were added to BM, osmolality increased roughly to 480 mOsm/kg with the first two fortifiers and only to 433±6 mOsm/kg with the third one. Upon addition of any of four different NSs to BM modified with AlmirónFortifier® and NANFM85®, osmolality reached values greater than 520 mOsm/kg, while osmolality of PreNANFM85® with two out of the four NSs remained below 490 mOsm/kg. NSs supplementing carbohydrates and hydrolysed proteins resulted into a higher increase of BM osmolarity. Osmolality increased significantly with time and, after 22h, only BM modified with PreNANFM85® remained below 450 mOsm/kg.

CONCLUSIONS

Upon addition of the HMFs tested, BM osmolality increases significantly and keeps raising over time. All HMFs but the recently developed PreNAN FM85® at 4% exceed the AAP recommended threshold for osmolarity of 450 mOsm/kg. Addition of NSs to PreNAN FM85® at 4% significantly increases osmolality above 450 mOsm/Kg. Thus, using PreNAN FM85® at 5% may be preferable to adding nutritional supplements since nutritional recommendations by the ESPGHAN are reached with a lower increase in osmolality.

Effect of Target Fortification on Osmolality and Microbiological Safety of Human Milk Over Time

OBJECTIVES

The fortification of human milk can result in increased osmolality, which may be associated with adverse effects for preterm infants. To evaluate the effect of target fortification on the osmolality and microbiological safety of donor human milk and raw mature milk during the first 72 hours of storage.

METHODS

We performed target fortification of 63 pasteurized donor human milk (PDHM) and 54 raw mature milk (RMM) samples in a laminar flow hood. Osmolality (mOsm/kg) was evaluated before fortification (T0), immediately after fortification (T1), at 6 (T2), 24 (T3), 48 (T4), and 72 hours (T5) after fortification. Microbiological analysis was performed at T0, T4, and T5. During the study, all samples were stored at 4°C.

RESULTS

Mean osmolality at each study point for PDHM and RMM were, respectively: T0: 291.4 ± 11.0 versus 288.4 ± 5.6 (P = 0.06); T1: 384.8 ± 16.7 versus 398.3 ± 23.7; T2: 393.9 ± 17.7 versus 410.1 ± 27.0; T3: 397.8 ± 17.6 versus 417.9 ± 26.1; T4: 400.0 ± 16.5 versus 420.2 ± 24.9; T5: 399.6 ± 16.5 versus 425.2 ± 25.8 (P < 0.001 from T1 to T5). Microbiological analyses were negative at each study points for PDHM. At T0 16.1% of RMM samples had positive cultures, whereas the bacterial count remained stable thought the study.

CONCLUSIONS

PDHM's osmolality increases during the first 6 hours after fortification and remains stable and safe until 72 hours. RMM's osmolality increases during the first 24 hours and remains stable and safe until 72 hours. The storage at 4°C and the manipulation of PDHM and RMM samples in a laminar flow hood seem to be safe and preserve the microbiological safety of fortified pasteurized human milk until 72 hours.