Increased morbidity − but equally good quality of life for prematurely born adults

Individuals with a birth weight of less than one kilogram have an increased risk of cerebral palsy, intellectual disabilities and attention deficit disorders. Nonetheless, they rate their quality of life as high as individuals with normal birth weight. This finding emerges from a new study of 201 adults who were born prematurely and followed from birth to the age of 26–29 in Sweden.

Developments in neonatal care have led to a dramatically increased rate of survival among prematurely born children with a birth weight of under 1,000 grams. However, there is still limited knowledge of how such premature birth affects health and well-being in adult life.

Follow-up from birth to adulthood

In a new Swedish study, researchers have investigated the health and quality of life of all children born in Sweden between April 1990 and March 1992 with a birth weight of no more than 1,000 grams. The study, known as the 1,000 g study, began immediately at birth.

When the participants were 26–29 years old, they were asked to complete a questionnaire about their self-rated quality of life, with reference to both physical and mental health. Data on registered diagnoses possibly linked to premature birth were obtained from national registers. The same procedure was also carried out for a control group consisting of 327 individuals with normal birth weight.

“We see clearly increased morbidity among the individuals born extremely prematurely, both in terms of physical health – such as lung function, sight, hearing and movement – and diagnoses related to brain function, for example, cognition, attention and social abilities,” says Maria Heyman, the first author of the study.

In the whole group with a birth weight of no more than 1,000 grams (371 individuals*):

• 10 per cent had cerebral palsy, compared with 0.5 per cent in the control group
• 10.2 per cent had an intellectual disability, compared with 1 per cent in the control group
• 13.7 per cent had an attention deficit disorder such as ADHD/ADD, compared with 4.4 per cent in the control group
• 10.5 per cent had autism, compared with 2.1 per cent in the control group
• Mental illnesses such as bipolar disorder and anxiety disorder were also more common than in the control group.

No difference in self-rated quality of life

Although physical and mental illnesses were more common among the prematurely born, those who participated in the study rated their quality of life as high as in the full-term control group. Despite more disabilities, many of the prematurely born do not perceive themselves to be limited in their daily life.

“Ultimately, the most important outcome may be how the prematurely born individuals themselves perceive their lives,” Heyman comments.

Although the current study evaluates neonatal care conducted approximately 30 years ago, the researchers argue that these findings are probably also applicable to children born today.

“Admittedly, the survival rate for prematurely born children has increased, but several studies show that the long-term outcomes have remained largely unchanged over the past three decades. We therefore consider that these findings provide the best available assessment when giving information today to parents of extremely premature children,” Heyman says.

* In the analysis of mental and physical morbidity, the researchers used Swedish national registers and included all individuals (371 in total) who were born with a birth weight of no more than 1,000 grams between April 1990 and March 1992. Of these, 201 individuals responded to the quality-of-life questionnaire.