Introduction

The major clinical outcomes that are important to preterm infants and their families are survival and normal long term neurodevelopment. In developed countries over the past 30 years, better perinatal care has considerably improved these outcomes. This article covers the prevalence of neurodevelopmental problems and their types.

Prevalence

For most preterm infants of > 32 weeks' gestation, survival and longer term neurodevelopment are similar to those of infants born at term. Overall, outcomes are also good for infants born after shorter gestations. Most infants survive without substantial neurodevelopmental problems and most go on to attend mainstream schools, ultimately living independent lives.

A few preterm babies, however, do develop important and lasting neurodevelopmental problems. The period between 20 and 32 weeks after conception is one of rapid brain growth and development. Illness, undernutrition, and infection during this time may compromise neurodevelopment. The clinical consequences can include serious neuromotor problems (principally cerebral palsy), visual and hearing impairments, learning difficulties, and psychological, behavioural, and social problems.

Brain growth and development of sulcation and gyration with increasing gestational age. Magnetic resonance images at the level of the central sulcus at: (A) 25 weeks; (B) 28 weeks; (C) 30 weeks; (D) 33 weeks; and (E) 39 weeks. With permission from Counsell SJ et al. Arch Dis Child 2003;88: 269-74

Most substantial impairment occurs in the 0.2% of infants born before 28 weeks' gestation, or with birth weights of < 1000 g (extremely low birth weight). The survival rate for extremely preterm infants has improved over the past decade, but the overall prevalence of neurodisability after preterm birth has not fallen. In a recent North American follow …