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Optimistic people not only have a more positive outlook on life but also benefit from better health. They have better physical and mental health, recover faster from illness, and live longer. However, individuals born preterm tend to show poorer physical and mental health and a higher mortality rate. But does that mean that adults born preterm are, because of their particular circumstances, also less optimistic and more pessimistic in their attitude towards life? To examine these long-term effects of preterm birth, more than 5,000 participants from Finland and the UK were examined, revealing a surprising outcome. Adults born preterm showed the same level of optimism as term born ones. However, other influences such as birth weight, parental education, and smoking during pregnancy appear to alter the level of pessimism in later adulthood.

Preterm birth (PTB) is known for its various negative impacts on health. These include a higher risk of physical, mental, socioemotional, and cognitive problems. To improve our understanding of the effects of PTB, a new study from Finland and the UK examined the levels of optimism and pessimism in preterm born young adults. People with high levels of optimism generally have better physical health, a higher health-related quality of life, are less likely to suffer from certain mental diseases, recover faster, cope better with physical and emotional stress, live longer, and subsequently have a lower risk of mortality.

A total of 5,072 participants from three independent studies were included in the assessment. The level of optimism and pessimism was self-reported by the participants via the Life Orientation Test-Revised. Co-variants could be birth weight, neurosensory impairment, and parental education, smoking during pregnancy, sex, mother’s age at birth, preeclampsia, maternal mode of delivery (caesarean section). Optimism and pessimism were calculated as independent variables.

Preterm born young adults show no difference in optimism levels

As preterm born adults often face health and well-being complications later in life, the study assumed that PTB adults would score higher in pessimism and lower in optimism. However, the assumption was proven wrong. There was no difference between the optimism scores in preterm and term born adults. PTB adults tended to have a slightly higher pessimism scores than term born adults, and the more preterm an individual was born, the higher their pessimism score. However, this tendency

was not significant, meaning that pessimism in adulthood is generally not associated with PTB. In addition, the degree of PTB had no influence on optimism, indicating that regardless of how preterm an individual was born, their optimism in later life cannot be predicted. Therefore, the study concludes that whether we have a positive outlook on life as adults and are consequently healthier does not depend on how early we are born.

It should be noted that even though the influence of PTB is statistically not significant for pessismism/optimism scores, it may be impactful for the individual. Preterm born adults more often face long-term adversities in terms of mental and physical health. Therefore, preterm born individuals still tend to score lower on optimism and higher on pessimism, even though this does not apply to everyone. However, other living circumstances were analysed and show a significantly higher influence on optimism in adulthood. Several co-variants related to pregnancy and childhood living conditions have a greater influence on optimism in adults than PTB.

Parents can influence their children’s optimism significantly

In general, men appeared to be more optimistic than women. Other factors that have a positive effect on optimism are no neurosensory impairment, a non-smoking mother, having parents with higher education, and a higher birthweight. Preterm born adults with low birth weight, but appropriate for gestational age, were also less likely to report depression and depressive symptoms later in life.

Lastly, the family environment also influenced the results. Parents of very preterm newborns who were appropriate for gestational age received more support than those of children who were small for their gestational age. Greater support in parenting increases the level of optimism, as higher birthweight fosters environments that promote an optimistic life orientation.

When analysing indicators for an optimistic or pessimistic attitude towards life, focusing solely on PTB proves to be rather reductive and does not reflect the complex realities of life in all its facets. Instead, PTB can be understood as one factor among many that indicates a tendency towards optimism or pessimism and interacts in a complex relationship with other, often more potent, indicators.

Paper available at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0259463

Ful list of authors: Rachel Robinson, Kati Heinonen, Polina Girchenko, Marius Lahti-Pulkkinen, Eero Kajantie, Petteri Hovi, Aulikki Lano, Sture Andersson, Johan Eriksson, Dieter Wolke, Sakari Lemola, Katri Räikkönen

DOI: https://doi.org/10.1371/journal.pone.0259463