According to an investigation in the September 21 issue of JAMA, an investigation that consisted of over 600,000 infants born in Sweden between 1973 and 1976, revealed that those who were born prematurely (less that 37 weeks gestation) had an increased risk of death during early childhood and young adulthood in comparison to those born full term.
In developed countries, premature birth is the leading cause of perinatal (pertaining to the period immediately before and after birth) illness and death. The authors explain: “Although the early effects of preterm birth are well documented, less is known about the longer-term outcomes in adulthood. These outcomes have a growing clinical and public health importance because of the high prevalence of preterm birth and improved early survival.” In the U.S. the frequency of premature births has increased to over 12%. “As a result, large numbers of individuals who were born preterm are now surviving to adulthood. A comprehensive understanding of their outcomes in adulthood is needed to enable earlier prevention, detection, and treatment of the long-term health sequelae.”
Casey Crump, M.D., Ph.D., of Stanford University, Stanford, Calif., and colleagues carried out an investigation in order to analyze the connection between gestational age of birth and mortality in young adulthood. The investigation involved a national cohort of 674,820 people born in Sweden between the years 1973-1979 who survived to one years old, including 27,979 (4.1%) who were born prematurely, who were followed up to 2008. In total 7,095 deaths occurred during follow-up from the age of one year to the maximum attained ages of 29 to 36 years.
They discovered a strong inverse connection between gestational age at birth and mortality in early childhood (ages 1-5 years). In late childhood (ages 6-12) and adolescence (13-17 years) no connection was observed, however, in young adulthood (18-36 years) an inverse connection returned. Premature birth was linked with increased mortality in early childhood and young adulthood, even among those who were born late preterm (34-36 weeks), in comparison to individuals born full-term.
The authors said:
“In young adulthood, gestational age at birth had the strongest inverse association with mortality from congenital anomalies and respiratory, endocrine, and cardiovascular disorders and was not associated with mortality from neurological disorders, cancer, or injury.”
To their knowledge, they write that this is the first investigation to report the specific contribution of gestational age at birth on mortality in adulthood:
“The underlying mechanisms are still largely unknown but may involve a complex interplay of fetal and postnatal nutritional abnormalities; other intrauterine exposures, including glucocorticoid (a steroid hormone) and sex hormone alterations; and common genetic factors.
Although most survivors have a high level of function and self-reported quality of life in young adulthood, our previous and current findings demonstrate the increased long-term morbidities and mortality that may also be expected. Clinicians will increasingly encounter the health sequelae of preterm birth throughout the life course and will need to be aware of the long-term effects on the survivors, their families, and society.”
