Both birth and survival rates of preterm infants have risen in recent years1. As a result, an increasing number of preterm infants are being discharged from hospital into the care of the primary care team. This can present challenges to GPs, health visitors and dietitians who may have limited experience caring for preterm infants.
Most infants born before 32 weeks’ gestation will continue under the care of the neonatal team and outreach services but those born at 32–36 weeks usually receive minimal or no hospital follow up. For all these babies, GPs and health visitors remain the first port of call for their general health needs.
It is important that primary care teams are aware of the needs of preterm infants and aware of warning signs of the many conditions which pose a particular risk to this group (see List 1). Growth is an important sign: poor growth may be due to inadequate nutritional intake, a poorly controlled respiratory disease or a number of other medical problems.
Key morbidities pre-discharge for preterm infants
- Sepsis and necrotising enterocolitis
- Respiratory distress syndrome (RDS)
- Brain injury (e.g. intraventricular haemorrhage)
- Hypoglycaemia and jaundice
Key risks and morbidities for preterm infants after discharge
- Poor nutritional intake and/or feeding difficulties
- Ongoing respiratory disease e.g. chronic lung disease
- Poor growth
- Increased risk of viral illness e.g. RSV bronchiolitis
- Neuro-developmental concerns
Neurodevelopment is a complex area and an over reliance on reaching ‘developmental milestones’ as a sole measure of progress can be inappropriate. However, most preterm babies in the first year of life will demonstrate (at corrected age post-term): smiling (6–8 weeks), increasing vocalisations (3–4 months), rolling over (5–6 months), sitting with support (6–8 months), sitting without support (9–10 months) and weight bearing or standing (10–12 months).
Preterm infants are at an increased risk of infections such as respiratory syncytial virus (RSV). It is sensible, therefore, to advise parents to avoid exposing their new baby to friends or relatives who may be suffering from a respiratory illness, and to promote good hand hygiene. This advice, however, should be kept in proportion to avoid raising undue concern in parents who may already be anxious about their infant’s health.
Preterm babies are born with inadequate stores of major nutrients, including protein, energy, minerals and vitamins2. Feeding should be carefully monitored, along with weight, linear growth and head circumference. When measuring growth and assessing neurodevelopment it is important to use the infant’s post-menstrual age, rather than age from birth. This will ensure that feeding choices are adapted to the infant’s needs and that milestones for development remain realistic. Assessment of growth is of primary importance in detecting undernutrition and while overnutrition is impossible with breast milk alone, some preterm babies on enriched formula may demonstrate excessive weight gain (upward crossing of centile lines) if continued on it for longer than they require and may be more appropriately managed by converting to a standard formula.
The gold standard for the nutrition of preterm infants is breastfeeding3. If necessary, breast milk can be supplemented by a breast milk fortifier (BMF) although, in practice, this tends to be discontinued once the infant has been discharged.
Breast milk is sufficient to meet the nutritional needs of preterm infants who leave hospital at a weight appropriate to their post-menstrual age, although they should also receive iron and vitamin D supplements. Healthy Start children’s vitamin drops contain recommended levels of vitamins A, C and D4. Children receiving 500ml or more of formula per day do not require extra vitamins but, if born preterm, should receive a formula with a high content of long-chain polyunsaturated fatty acids5.
Infants discharged with a subnormal weight for post-conceptional age are at increased risk of long-term growth failure, and the human milk they consume should be supplemented with a human milk fortifier to provide an adequate nutrient supply. If formula-fed, such infants should receive special post-discharge preterm formula with higher levels of protein, minerals, trace elements and long-chain polyunsaturated fatty acids5.
Many hospitals supply parents with two tins of post-discharge formula. This is available on prescription and can be continued for up to six months depending on the infant’s progress. Other hospitals advise parents to visit their GP to get their first prescription of post-discharge formula ahead of time to ensure that it is ready when the infant is discharged. Those on a post-discharge formula do not require additional mineral or vitamin supplements. If, however, the infant is switched to a regular formula, the infant may require additional iron and vitamin D supplements.
Continued monitoring of the preterm infant’s growth, development and ability to feed successfully is essential. If weight gain begins to falter and drops away from the expected percentile line on a growth chart, referral back to the neonatal or paediatric team should be considered.
Dr Nicholas D Embleton BSc MD FRCPCH is a consultant neonatal paediatrician at Royal Victoria Infirmary, Newcastle-upon-Tyne
Lynne Paterson RGN RM BSc MA is a neonatal nurse consultant at James Cook University Hospital, Middlesbrough