The effect of very preterm birth on the Five-Factor Model of personality traits: A meta-analysis of individual participant data

There is mixed evidence on personality differences among those born very preterm or with very low birth weight (VP/VLBW). This meta-analysis of individual participant data aimed to examine differences in personality traits between VP/VLBW (n = 568) and term-born (n = 1,060) adults, and the role of neonatal characteristics and neurosensory impairments in childhood, which have not been previously investigated. Six studies were identified from two research consortia and a systematic search of the literature (PubMed and Scopus); studies were eligible if they included VP/VLBW and term-born adults followed from birth and assessed personality using the Five-Factor Model. Risk of bias (Newcastle-Ottawa Scale) was generally not a concern apart from the use of self-reported measures and the rate of follow-up. Using a one-stage approach, VP/VLBW scored lower on extraversion and openness and higher on neuroticism and agreeableness than term-born participants after adjusting for sex and parental education. Within the VP/VLBW group, those with bronchopulmonary dysplasia scored lower on extraversion and higher on neuroticism, with similar findings after removing participants with neurosensory impairments. Altogether, these findings suggest that a proportion of the effect of VP/VLBW birth on personality may be attributed to neonatal morbidities and altered brain development, although other confounding factors require further research.