Bronchopulmonary dysplasia, a type of chronic lung disease, is a risk factor for the development of cerebral palsy (CP) in preterm infants, a new study shows.
The study, “Association between bronchopulmonary dysplasia and cerebral palsy in children: a meta-analysis,” was published in the journal BMJ Open.
Studies have shown that prenatal factors, including maternal age, education, obesity, race, chorioamnionitis (an inflammation of the fetal membranes) and high blood pressure can contribute to the development of CP in a fetus.
Bronchopulmonary dysplasia (BPD) — a form of chronic lung disease that affects newborns and infants — has been implicated as a potential neonatal risk factor for CP.
BPD, common in preterm and low birthweight infants born at 24–26 weeks of gestation, develops after mechanical ventilation or oxygen inhalation, usually in certain premature infants with respiratory distress syndrome.
As cerebral palsy, cognitive delay and hearing loss are commonly reported complications in very premature infants, researchers hypothesized that BPD could lead to neonatal brain injury and subsequent development of CP.
Several studies have investigated the relationship between BPD and CP in premature infants. However, the association between the two disorders has been inconsistent across studies.
Researchers conducted a meta-analysis to evaluate the potential association between BPD and CP in preterm infants. A meta-analysis is the statistical procedure for combining data from multiple studies in order to find a common effect or trend.
In particular, researchers looked for the prevalence of developing CP after an infant has been exposed to BPD. The meta-analysis included 11 studies.
According to the statistical model, BPD was significantly associated with CP in preterm infants. Infants with BPD had 2.1 times the risk of developing CP compared to infants without BPD.
Six studies evaluated the association between BPD (oxygen dependence at 36 weeks) and CP in premature infants, and only one reported no significant association between the two.
In five studies, researchers evaluated the association between BPD and CP and controlled for gestational age. The association between BPD and CP remained significant in both the adjusted or unadjusted results.
Factors that contribute to the varying results include study design, the definition of BPD, the time of diagnosis of CP and whether the studies adjusted for potential confounders, such as gestational age or sex.
Researchers highlighted the need to develop a standardized definition of BPD, as most published reports do not apply specific diagnostic criteria for BPD.
“This study suggests that BPD is a risk factor for CP. Further studies are required to confirm these results and to detect the influence of variables across studies,” the researchers concluded.