Paediatrics: Prematurity

Prematurity

Birth before 37 completed weeks gestation. 8% of all births. Most prob-lems seen in with infants born <32 completed weeks (72% of all births).

Predisposing factors

·  Idiopathic (40%).

·  Previous preterm birth.

·  Multiple pregnancy.

·  Maternal illness, e.g. chorioamnionitis, polyhydramnios, pre-eclampsia, diabetes mellitus.

·  Premature rupture of membranes.

·  Uterine malformation or cervical incompetence.

·  Placental disease, e.g. dysfunction, antepartum haemorrhage.

·  Poor maternal health or socio-economic status.

Associated problems

·  Respiratory: surfactant deficiency causing respiratory distress syndrome, apnoea of prematurity, chronic lung disease/bronchopulmonary dysplasia (CLD/BPD).

·  CNS: intraventricular haemorrhage, periventricular leucomalacia; retinopathy of prematurity.

·  GI: necrotizing enterocolitis; inability to suck; and poor milk tolerance.

·  Hypothermia.

·  Immuno-compromise resulting in ‘rise’risk and severity of infection.

·  Impaired fluid/electrolyte homeostasis (i transepidermal skin water loss, poor renal function).

·  Patent ductus arteriosus.

·  Anaemia of prematurity.

·  Jaundice.

·  Birth trauma.

·  Perinatal hypoxia.

·  Later: increased risk of adverse neurodevelopmental outcome, behavioural problems, sudden infant death syndrome (SIDS), non-accidental injury (NAI), and/or parental marriage break up (due to impaired infant–maternal bonding, stress of long-term complications, etc.).

General management—antenatal

·  Delivery should be planned in a centre capable of caring for preterm infants.

·  If a woman has threatened preterm labour in a centre unable to care for the baby, possible in-utero transfer should involve discussion between neonatology and obstetrics teams preferably at consultant level. Consider foetal fibronectin screening to aid diagnosis and tocolysis to delay birth to allow for transfer.

·  Give mother IM corticosteroids, 2 doses, 12–24hr apart, of either beta- or dexamethasone, if <34wks gestation. Steroids ‘fall’ mortality by up to 40% (d severity of RDS, periventricular haemorrhage, and necrotizing enterocolitis) provided they are given >24hr before birth. Benefit persists for at least 7 days. Effect of repeated doses remains unclear—may have adverse impact on later growth.

General management—postnatal

·Most preterm infants require stabilization and support in transition– not resuscitation.

·Senior paediatrician should be present at birth if very preterm, e.g. <28wks.

·Delay cord clamping for 1min if infant not compromised.

·Immediately after birth, place in food grade plastic bag and under radiant heater.

·Provide respiratory support as required:

o use positive end-expiratory pressure (PEEP) (5cmH₂O);

o start with lower peak inspiratory pressure or proximal (PIP) (20cmH₂O);

o consider elective intubation and ETT surfactant if <27/40;

o may be possible to stabilize with PEEP/nasal continuous positive airway pressure (CPAP) only.

·Monitor oxygen saturation levels if available (right wrist = pre-ductal), and target oxygen therapy appropriately:

o must be familiar with normal values;

o approx 10% well preterm infants will have SpO₂ <70% at 5min;

o ‘correct’ starting dose of O₂ unclear, therefore, can start in air;

o easy to hyperoxygenate if start in high FiO₂.

·Once stable, well infants >1800g, and >35/40 may be transferred to a suitable postnatal ward if midwifery staffing and expertise exists for the required additional care. Otherwise admit to a neonatal unit.

·Measure weight and temperature on admission and monitor closely:

o <1000g 37–37.5C;

o >1000g 36.5–37C;

o nurse in 80% humidity for first 7 days if <30/40.

·Monitor and maintain blood glucose with enteral feeds (expressed breast milk), total parenteral nutrition (TPN) or 10% glucose as appropriate. Encourage ALL mothers to express breast milk from day 1.

·Start broad spectrum antibiotics if any possibility of infection, e.g. benzylpenicillin, and gentamicin.

·Start specific treatment for associated diseases and complications of prematurity, e.g. surfactant for RDS.

·Aim for minimal handling of infant with appropriate levels of noise and cycled lighting in the nursery.

·  Support parents.