Preterm birth is a risk factor for having chronic obstructive pulmonary disease (COPD) or asthma as an adult, according to study findings published in the European Respiratory Journal.
Investigators aimed to explore the association between gestational ages and obstructive airway disease (COPD and/or asthma) through assessment of a population of adults aged 18 to 50 years. Additionally, the researchers explored whether this association differed among individuals born preterm and diagnosed with bronchopulmonary dysplasia (BPD) or those who were born small for gestational age (SGA).
The researchers conducted a population-based register study using medical birth registers that included all live births in Norway from 1967 to 1999 (n=1,669,528) of which 5.0% were preterm and in Finland from 1987 to 1998 (n=706,717) of which 4.8% were preterm. Specialized health care registers in Norway (2008-2017) and in Finland (2005-2016) were used to obtain data concerning care episodes of COPD or asthma.
Ultrasonography was not used in Norway to confirm duration of gestation until December 1998 and was not used in Finland until the late 1980s or early 1990s. Prior to that, clinical examination or data on the last menstrual period was used to estimate duration of gestation. Gestational age was defined as extremely preterm (23-27 weeks), very preterm (28-31 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), full term (39-41 weeks, reference) and post-term (≥42 weeks).
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Preterm birth should be recognized as a risk factor for obstructive airway diseases in adulthood, and full medical history for people presenting with respiratory symptoms should include key perinatal data such as birth weight, gestational age and key pregnancy conditions.
For individuals born extremely or very preterm, investigators found that odds of any obstructive airway disease in early adulthood were 2- to 3-fold compared with individuals born full term. These odds were 1.1- to 1.5-fold among individuals born moderately or late preterm, or early term compared with individuals born full term.
Investigators noted that for those 30 to 50 years of age with COPD, the odds ratio was 7.44 (95% CI, 3.49-15.85) for those born extremely preterm; 3.18 (95% CI, 2.23-4.54) for those born very preterm; 2.32 (95% CI, 1.72-3.12) for those born moderately preterm. Study authors found subgroup associations similar among people 18 to 29 and 30 to 50 years of age and among people in the Norwegian and Finnish databases.
For asthma, the risk was higher in all groups born preterm except for those born in Finland moderately preterm.
Odds of any obstructive airway disease in adulthood were further increased for those born extremely or very preterm if they experienced BPD in infancy.
Individuals born early term and extremely, very, and late preterm in Norway and those born early term and very preterm in Finland compared with those born full term, had higher odds for obstructive airway disease if they were born SGA.
Study limitations include unverifiable diagnoses and pregnancy dating based on last menstrual period.
“Preterm birth should be recognized as a risk factor for obstructive airway diseases in adulthood, and full medical history for people presenting with respiratory symptoms should include key perinatal data such as birth weight, gestational age and key pregnancy conditions,” investigators concluded. Investigators stated that among very or extremely preterm-born individuals, “the excess risks are clinically significant and call for particular diagnostic vigilance,” when these individuals present with respiratory symptoms.
