Caesarean delivery and risk of childhood asthma development: meta-analysis

Introduction
Several studies indicate that delivery by caesarean section may be one of the risk factors for the development of childhood asthma.

Aim
A meta-analysis was carried out to establish the relationship between delivery by caesarean section and asthma in children.

Material and methods
After a review of bibliographic databases, 41 articles were obtained and 12 of which were accepted for further analysis. The odds ratios (OR) included in the analysis were specified on the basis of data from the presented studies or were calculated using reported prevalence. The analysis took into account unadjusted OR. The heterogeneity of results was assessed using the c2 test, determining p < 0.05 as the level of significance. The analysis was performed using Statistica 13.3 and kit 4.0.67.

Results
Caesarean delivery was associated with an increased risk of development of childhood asthma (OR = 1.41); however, significant heterogeneity of results was demonstrated. A significantly higher risk of asthma was found in children born by caesarean section in the case where the disease was confirmed in a questionnaire-based study (OR = 1.26, 95% CI: 1.05–1.5), and the results of that study were homogeneous.

Conclusions
In the case of the diagnosis of asthma declared by parents in the questionnaire-based study, a significantly higher risk of disease occurrence was observed in children born by caesarean section. Due to the significant heterogeneity of the results of the studies, it cannot be clearly stated that caesarean delivery is a risk factor for the development of bronchial asthma.