BORN TOO EARLY

The outcome for a baby destined to be born prematurely can be improved by the administration of corticosteroids to the mother, preferably at least 48 hours before delivery. This increases surfactant production by the fetus, reduces the risk and the severity of the respiratory distress syndrome, increases survival and reduces other morbidities. When there has been prolonged rupture of membranes, administration of antibiotics to the mother reduces the risk of sepsis in the newborn. Where possible, delivery should be planned so that the neonatal team and their equipment are fully prepared and experienced members of staff are available. The parents should be counselled about what to expect and the outcomes for a baby born prematurely. The importance of expressing breast milk as soon as possible after delivery should be emphasized. At delivery, the immediate management priorities for a premature baby are similar to those for any other baby. However, heat loss will be greater, as they are smaller, the lungs are stiffer due to surfactant deficiency and are more fragile, and the premature baby will have fewer metabolic reserves. The baby should be dried and covered, or placed in a plastic bag under a radiant heater. The baby should be assessed for breathing, heart rate, colour and tone, and the airway positioned optimally. The baby will need respiratory support, which may be non-invasive continuous positive airways pressure (CPAP), or intubation. Surfactant may need to be administered in the delivery room. Excessive positive pressure ventilation (which may cause a pneumothorax) and hyperoxia should be avoided. The baby should then be transferred promptly to the neonatal unit. The chest radiograph shows airspace shadowing consistent with respiratory distress syndrome (RDS, also known as hyaline membrane disease or surfactant deficiency disease). Surfactant is produced by type II pneumocytes and its production by the fetus increases towards term. Deficiency of surfactant results in poorly compliant, lowvolume lungs, with ventilation–perfusion mismatching. Although surfactant production will increase after delivery, this can be impaired by acidosis, hypoxia and hypothermia. Clinical features include grunting, tachypnoea, chest recession and cyanosis. Exogenous surfactant can be administered via an endotracheal tube and can be given electively to very premature babies, who are very likely to develop RDS, or as rescue treatment when RDS becomes apparent.

Complications of premature birth

• Respiratory – RDS, pneumothorax, apnoea, chronic lung disease

• Cardiovascular – patent ductus arteriosus

• Neurological – periventricular haemorrhage, periventricular leucomalacia

• Gastrointestinal – necrotizing enterocolitis, gastro-oesophageal reflux

• Infection – group B Streptococcus, nosocomial infection

• Metabolic – hypoglycaemia, jaundice, rickets

• Iatrogenic – extravasation injury, pressure sores

KEY POINTS

• Antenatal corticosteroids improve the outcome of premature infants.

• Respiratory distress syndrome is common in premature babies.

 • Endotracheal administration of surfactant is used to treat respiratory distress syndrome.