Objectives To examine very preterm (gestational age at birth <32 weeks) and/or very low birth weight (birth weight <1500 g: VP/VLBW) adults’ personality and risk taking when compared with term controls. To investigate whether differences between VP/VLBW adults and controls remain after taking their general cognitive abilities into account.

Design The Bavarian Longitudinal Study is a geographically defined prospective cohort study of neonatal at-risk children born in 1985/1986 in Germany. A total of 200 VP/VLBW and 197 controls completed main outcome measures including broad autism phenotype, personality traits (eg, introversion, neuroticism), and risk taking at 26 years of age.

Results When compared with term controls, VP/VLBW adults scored significantly higher in autistic features, introversion and neuroticism but not in conscientiousness and closeness scales. They also reported lower risk taking. Profile analysis showed higher introversion, autistic features and neuroticism and lower risk taking as unique features of VP/VLBW adults (F_within-group=0.81, ns; F_{between-group}=49.56, p<0.001). These characteristics were found to load onto a single profile factor which was equivalent between the VP/VLBW and control samples (χ²=12.49, df=7, ns; comparative fit index=0.98). VP/VLBW birth significantly predicted the profile factor (β=0.33, p<0.001) and explained 11% of its variance. Adjusting for general cognitive deficits did not alter the findings.

Conclusions VP/VLBW birth poses an important risk for a global withdrawn personality, as indicated by being less socially engaged (introversion), low in taking risks, poor in communication (autistic features) and easily worried (neuroticism). This profile might help to explain the social difficulties VP/VLBW individuals experience in adult roles, such as in peer/partner relationships and career.