Healthcare (Commonwealth Union) – Premature births usually occur when a baby is born 37 weeks before pregnancy. A pioneering 34-year longitudinal study, with collaborations led by the University of Warwick in the UK, has followed individuals born extremely early from infancy into adulthood, revealing that early cognitive abilities are the most important factor in determining whether they thrive or encounter challenges later in life.
New findings published in JAMA Pediatrics show that most people born very preterm or with very low birth weight successfully develop stable and fulfilling lives by their mid-30s. However, approximately 20% continue to experience a range of long-term difficulties affecting areas such as career stability, romantic partnerships, and social relationships.
The Bavarian Longitudinal Study, directed by Professor Dieter Wolke at the University of Warwick, monitored 416 participants over more than three decades. Of these, 214 were born very preterm (before 32 weeks of pregnancy) or with very low birth weight (below 3.3 pounds/1.5 kilograms). Beginning at birth in the mid-1980s and continuing until participants reached 34 years of age, the research represents one of the world’s longest-running studies tracking outcomes among individuals born prematurely.
Based on comprehensive life-course interviews examining factors such as risk-taking behaviors, financial stability, and relationships with parents, romantic partners, and friends, researchers identified three main categories of adult outcomes. The optimal functioning group included individuals who were thriving across most aspects of life, accounting for 74% of those born full term and 56% of those born preterm. The moderate functioning group represented people who were generally successful but experienced challenges in romantic relationships and achieved lower levels of economic success, comprising 24% of full-term and 26% of preterm individuals. The low economic and social functioning group consisted of those facing significant difficulties with finances, friendships, and partnerships, affecting only 1.5% of full-term adults but 18% of adults born preterm.
Dr. Elif Gönen from the Department of Psychology at the University of Warwick indicated that the findings revealed that slightly more than half of individuals born extremely prematurely or with very low birth weight achieved strong outcomes across areas such as avoiding risky behaviours, financial stability, and social relationships. In contrast, 18% of this group experienced low overall functioning, compared with only 1.5% of those born at full term.
She added that adults in the low-functioning category reported significantly lower levels of life satisfaction compared with people in the other groups.
To identify the factors influencing these adult outcomes, researchers assessed a broad range of childhood characteristics, including premature birth status, gender, self-regulation skills, parenting approaches, friendships during primary school years, family financial circumstances and background, the home environment, and the quality of the parents’ relationship.
While several individual factors were initially associated with better adult outcomes — such as being born full term, showing greater persistence in childhood, and experiencing supportive parenting — the analysis revealed that only one factor remained a strong independent predictor when all influences were considered together: IQ measured at age eight.
A 15-point difference in childhood IQ, which is approximately the average gap between children born very preterm and those born at full term, was linked to a 79% lower likelihood of experiencing poor economic and social outcomes in adulthood.
Professor Dieter Wolke of the Department of Psychology at the University of Warwick says “For decades, the question we’ve been asked most is whether children born very preterm are destined to struggle for life. This study gives a hopeful and nuanced answer. Most people born very preterm are getting on well in their thirties, building careers, relationships and friendships much like everyone else. But there is a substantial minority who continue to face real difficulties, and they tell us their lives feels hard and not very satisfying.
