Conception via in vitro fertilization and delivery by Caesarean section are associated with paediatric asthma incidence

Background: The association between perinatal factors and asthma inception is under rigorous investigation. Nevertheless, evidence of a correlation between asthma, conception via in vitro fertilization (IVF) and delivery through Caesarean section (C-section) is inconclusive.

Objective: We aimed to assess the relation of asthma incidence with IVF and C-section, after controlling for several potential confounding factors.

Methods: Parent-reported wheeze in the last 12 months (current), wheeze ever, physician-diagnosed asthma, method of conception, and type of delivery were recorded from questionnaires filled in by the parents of 2016 Greek children aged 9-13, (the Healthy Growth Study population). Some perinatal data were recorded from children's medical records and others were reported by parents; anthropometric measurements were also conducted in children.

Results: IVF was correlated with physician-diagnosed asthma (OR = 2.25; 95% CI = 1.11-4.56), but not with current/ever wheeze after adjustment for potential confounding factors. After adjustment, C-section was also associated with asthma (OR = 1.39; 95% CI = 1.04-1.87), but not with current/ever wheeze. When the association of both IVF and C-section with asthma was examined in the same multivariate logistic regression model, it was weakened to borderline significance (OR = 2.04; 95% CI = 1-4.15 and OR = 1.34; 95% CI = 1-1.81 respectively).

Conclusions and clinical relevance: Conception via IVF and delivery by C-section may predispose children to future asthma development. Either variable could also exert a confounding effect on the link of the other to asthma; this may partially be accountable for inconsistencies in the findings of pertinent studies.