Neonatal complications following preterm birth.

Improvements in neonatal intensive care during the last 20 years have increased the survival of the most immature newborns at 23 weeks from 0% to 65% at some centres, although rates vary widely among neonatal care centres. University of Utah, USA data show that each week in utero after week 23 raises survival by 6-9%, to 90% by 27-28 weeks and 95% by 33 weeks. Provision of care in specialised centres to provide high-risk obstetric and neonatal intensive care, prenatal treatment with corticosteroids, postnatal treatment with surfactant and nitric oxide, and improvements in respirators and equipment to care for extremely immature infants all contribute to these changes. The increased rate of survival for extremely premature newborns has not been accompanied by an increased rate of severe intraventricular haemorrhage or neurological impairment, such as cerebral palsy. Regardless, intraventricular haemorrhage remains a significant problem, especially if associated with post-haemorrhagic hydrocephalus, leading to long-term neurological impairment and decreased survival. Necrotising enterocolitis (NEC) is more common in premature than in term newborns and is the most frequent cause of short bowel syndrome in infancy. Survival after surgery for NEC has improved during the last two decades, but complications of nutritional support produce many long-term problems. Retinopathy of prematurity (ROP) remains a frequent cause of neurosensory impairment for extremely premature newborns. Laser photocoagulation for advanced ROP is more effective than cryotherapy for preventing retinal detachment and improving visual outcomes. Despite prenatal corticosteroid treatment and postnatal surfactant administration, many extremely premature newborns still develop bronchopulmonary dysplasia. Abnormal pulmonary function may persist into adulthood, but newer ventilators and management schemes appear to be reducing this long-term morbidity. Many changes in neonatal care occur each year, but carefully controlled outcome studies are needed to evaluate the effectiveness of these newer styles of neonatal intensive care.