Background

It is well known that premature birth is associated with poorer long-term cognitive and developmental outcomes compared to infants born at term. In particular, there has been a large amount of work investigating the consequences of extreme prematurity (Wood 2000). However, far less is known about the long-term outcomes of premature infants born after 32 weeks gestation, often referred to as 'late preterm', who often have a relatively smooth neonatal course. A report by the American Academy of Pediatrics highlighted late preterm infants as a 'population at risk', whilst acknowledging a lack of research demonstrating long-term medical, neurological and developmental outcomes for these infants (Engle 2007).

A large US study has shown an increased risk of developmental delay in late preterm infants as compared to those born at term, although this only examined outcomes up to five years of age (Morse 2009). Another US study demonstrated poorer school outcomes in those born at 32 to 33 weeks gestation compared to full term infants, although this only looked at outcomes up to age 11 (Chyi 2008). A Swedish cohort demonstrated those born at late preterm were less likely to enter higher education compared to term infants but did not examine school performance throughout childhood (Lindstrom 2007). The cohort also demonstrated those born late preterm were more likely to be living with parents into adulthood than those born at term. To our knowledge educational and social outcomes have not yet been investigated in a group of late-preterm infants in the UK. Previous work using ALSPAC has investigated IQ at age 8 in late preterm infants (Odd, unpublished), but as yet has not examined school or social outcomes.

The aim of this project is to examine educational and social outcomes of infants born between 32 and 36+6 weeks of gestation when compared to those born at full term, generally defined as a gestation 37 weeks or greater.

Use of ALSPAC data

The ALSPAC cohort comprises a large number of young people, giving good statistical power for comparing infants born at different gestational ages. The detailed data collected over many years allows examination of and adjustment for potential confounding factors such as socioeconomic status. Collecting new data would incur a large financial cost, and a longitudinal approach would take many years before yielding results. Compared to extremely preterm infants, the neonatal management of late-preterm infants has not changed significantly over the past twenty years, and so it would be reasonable to use the findings of this study to make recommendations for infants born at late preterm today. Finally, the ongoing contact with the original cohort allows the potential for a recall study in the future (see long-term plan below).

Long-term plan/project team

Phil Peacock is currently working as an Academic Clinical Fellow in Paediatrics, and planning to undertake a PhD from September 2012. His work is being supervised by Prof Alan Emond, Prof John Henderson and Dr David Odd. The initial plan is to conduct a small study investigating Key Stage 1 educational outcomes in the interest group during a 6 month full-time research block, commencing September 2010. Following on from this, the aim is to prepare a PhD proposal to fully investigate educational and social outcomes with late preterm infants in ALSPAC. A proposed extension to the secondary data analysis is to recall a group from ALSPAC who were born at 32 to 36 weeks gestation and conduct MRI head scanning to examine long-term neuroradiological findings. Separate ALSPAC approval, as well as appropriate ethics approval and funding, will be sought if it is decided to pursue this.