Maternal expressed breast milk / mother's own milk
Maternal expressed breast milk (MEBM), also known as mother’s own milk (MOM) is the optimal feed for preterm babies. It confers many short and longer term health benefits which are described in more detail in the recently updated World Health Organisation (WHO) recommendations for the care of preterm and low birth weight babies38.
Donor human milk
In the absence of sufficient MEBM donor human milk (DHM) is recommended in preference to infant formula (IF) for babies <32 weeks GA and / or <1500 grams38, 39, 40. High quality evidence of benefit from DHM is limited, but a consistent finding when compared to IF is that DHM reduces the incidence of preterm NEC41, 42.
It is important to acknowledge that DHM is fundamentally different to MEBM. DHM undergoes multiple processes e.g. freezing, transportation and pasteurisation prior to being fed, which have an impact on the biochemical, immunological and nutritional composition when compared to fresh and frozen MEBM. Parents should always be counselled of the differences between MEBM and DHM, highlighting that optimal outcomes are based on MEBM, and that DHM is ideally a bridge to achieving this. Ongoing maternal lactation support should always be provided in conjunction with DHM use, and parental consent for use must be obtained. Further information on DHM, the existing evidence base and ongoing uncertainties is available in the updated British Association of Perinatal Medicine Framework for Practice on Donor Human Milk Use in Neonates39 (The Use of Donor Human Milk in Neonates | British Association of Perinatal Medicine (bapm.org) )
Ideally DHM is replaced by MEBM once maternal lactation is established, but in the continued absence of sufficient MEBM the options include continuing with DHM beyond the highest risk window for NEC i.e. >34 weeks corrected GA or grading over to a preterm formula (PTF). If DHM is continued fortification should be considered as per MEBM (see below).
There is insufficient evidence to make specific recommendations about either duration of DHM use or routine fortification of DHM. However it is important than neonatal units and networks work collaboratively to produce and adhere to guidelines that ensure DHM use is consistent. See the BAPM recommendations below39
Multicomponent breast milk fortification
The benefits of MEBM have been described above, however human milk alone (maternal and / or donor) at volumes of ≤200 ml/kg does not have the nutrient density, particularly of protein, calcium and phosphorus to meet the increased nutritional requirements of a preterm baby43. For this reason supplementation with a multicomponent breast milk fortifier (BMF) is recommended. It should be noted that although most studies of BMF show slightly greater weight, length and head growth, and no demonstrable increase in NEC there is no consistent data showing improvements in longer term developmental outcomes44.
For further advice see the guideline for Expressed breast milk
Preterm infants less than 32 weeks’ gestation should receive supplementary phosphorus which should be titrated against normal serum phosphate and ALP levels- see Bone Health guideline.
Which babies should receive breast milk fortification?
There is insufficient evidence to make specific recommendation on which subgroups of preterm babies may benefit most from BMF and we therefore recommend that fortification should be considered in all babies born ≤32 weeks GA or ≤34 weeks GA with a birthweight of ≤1800 grams.
Fortification may not be required if ≥50% of the feed requirement is provided by preterm formula, although it can be considered if there is poor growth and suboptimal tolerance of volume. BMF should never be added as a supplement to preterm formula.
When should breast milk fortification be started?
The optimal time to start BMF is not clear and practice varies across the UK. Early fortification seems to be as safe as delayed fortification and it may reduce accrued nutrient deficiencies, positively influencing bone metabolism45. ESPGHAN suggest starting BMF when enteral intakes reach 40–100 mL/kg/day7 however this is considerably earlier than most neonatal units in Scotland have traditionally introduced fortification.
We recommend a move towards earlier consideration of fortification once milk volumes ≥120 mL/kg/day have been tolerated for at least 24 hours. This will help to mitigate the recognised reduction in nutritional intake and associated growth failure when PN stops28-31.
Which breast milk fortifier?
Currently bovine based, multi-nutrient BMF are recommended for routine clinical practice. The following are both produced in powder form and packaged into sachets:
- Nutriprem BMF (Cow & Gate) - contains extensively hydrolysed protein, carbohydrate, vitamins and minerals. Halal & Kosher certified
- SMA BMF (Nestle) – contains partially hydrolysed protein, carbohydrate, vitamins and minerals, including iron. Halal certified
Human milk derived BMF are now commercially available either as concentrated liquids or lyophilized powders which make an exclusive human milk diet possible. They are expensive when compared to bovine based fortifiers and to date systematic reviews do not show clear benefit of their use over current practice of using a bovine based fortifier, and they are not routinely recommended at this time46.
When should BMF be stopped and when should post discharge fortification be considered?
Traditionally BMF have been stopped before discharge once breastfeeding is established. However there is evidence that babies who have not reached term benefit from continued milk fortification to ensure that their intake of critical nutrients (especially protein and minerals) is maintained47. This combined with the introduction of home nasogastric feeding policies to facilitate earlier discharge mean that continuation of BMF at home is becoming established into practice.
We recommend that post discharge fortification is considered in the following babies:
- Those <37 weeks CGA and / or ≤1800 grams, especially if there has been inpatient growth faltering and growth parameters have dropped >2 centiles from birth
- When breast feeding is still being established
Fortification is generally not required beyond 6 weeks CGA and if growth remained suboptimal at this stage medical review and dietetic referral should be considered. A guideline to provide greater clarify on the practice is currently being written.
Preterm formula
Preterm formula (PTF) have been designed to meet the increased nutrient requirements of preterm babies and to support adequate growth. They are not recommended for growth restricted term babies and are only available in hospital settings.
PTF are recommended when MEBM and / or DHM are unavailable in babies born <34 weeks GA and are used until babies reach 2000 grams and / or 37 weeks CGA.
- If using SMA Gold Prem 1, volumes should be maintained at 150 mL/kg/day to avoid excessive protein intake
- If using Cow & Gate Nutriprem 1, volumes can be increased up to 165 mL/kg/day as indicated by weight gain and volume tolerance
SMA Gold Prem 1 is partially hydrolysed. Cow & Gate Hydrolysed Nutriprem is extensively hydrolysed however the benefit of hydrolysed milk use in neonatal settings is yet to be substantiated48.
Nutrient enriched post discharge formula
Nutrient enriched post discharge formulae (NEPDF) can be considered when a preterm baby reaches >37 weeks CGA and / or >2000 grams if:
- Growth has been poor i.e. growth parameters have dropped >2 centiles from birth and catch-up growth is required
- There are associated co-morbidities, such as BPD which result in a higher nutrient requirement
It should be noted that meta-analyses of NEPDF have not shown any consistent improvements in longer term growth outcomes49 and a decision to use it should be discussed within the MDT on a case by case basis. The majority of preterm babies with normal growth velocity do not require NEPDF.
There are two NEPDF available in the UK; Nutriprem 2 and SMA Gold Prem 2. Both are available on prescription and should be added to discharge prescription request. Once introduced they are continued until adequate catch-up growth has been achieved or until 6 months CGA.
Term formula
In the absence of MEBM, term formula are indicated for late preterm babies 34-37 weeks GA with normal growth velocity and no requirements for catch-up growth.
Specialised term formula
Specialised term formulae are not designed to meet the requirements for preterm babies and will require modification to ensure individual requirements are met. These should only be used where absolutely necessary and under the direction of a specialist neonatal dietitian.
These are not available as ready to feed preparations, and if reconstituted out with a specialist milk kitchen they need to be prepared in accordance with the Department of Health guidelines50, 51.
Nutritional supplements – vitamins & minerals
Babies born prematurely have lower stores of fat soluble vitamins, and potentially higher requirements for all vitamins and minerals than those born at term. High quality evidence to guide supplementation is lacking which has led to variation in practice. Please see local monographs for current unit policies.
Probiotics
Evidence from randomised controlled trials and meta-analysis suggest that administration of probiotics to preterm babies reduces their risk of severe NEC and death53, 54. A variety of probiotic preparations have been studied and although preparations using combinations of organisms appear to confer the greatest benefit there is still uncertainty about which is the optimal preparation55.
Probiotics are not licensed as medicines, rather they are characterised as a food product and regulated in a similar way to breast-milk fortifier. The two most commonly used preparations in the UK are56:
- Labinic (Biofloratech Ltd, UK) which contains Lactobacillus acidophilus, Bifidobacterium infantis and Bifidobacterium bifidum. This is a liquid preparation and the dose is 5 drops (0.2ml) daily. The cost is 64p per dose
- ProPrems (Neobiomics AB, Sweden) which contains Bifidobacterium infantis Bifidobacterium lactis and Streptococcus thermophiles. This is a powder preparation and the dose is one sachet (0.5g) mixed into 13ml of milk or sterile water daily. The cost is £5.90 per dose
Practicalities of introducing probiotics into clinical practice
- Although not licensed as a medicine in the UK, it is important to ensure appropriate delivery, dosage and governance when introducing probiotics onto the neonatal unit
- They should be prescribed on the neonatal drug prescription chart and administered after checking by two nurses in the same way as for a medicine
- An appropriate information leaflet should be available for families
- Sepsis with probiotic organisms has been described and the local microbiology team should be made aware if probiotics are introduced into practice. These organisms are sensitive to standard antibiotics and grow on conventional culture media
Criteria for use
- Start probiotics in babies <32 weeks GA or <1500 grams within 48 hours of commencing enteral feeds
- Continue probiotics until 34 weeks CGA
- Withhold daily dose in babies who are seriously unwell / septic due to the potential risk of translocation of probiotic bacteria in this situation
- Withhold daily dose in babies who are nil by mouth for a suspected gastrointestinal surgical diagnosis