Asthma and atopy in children born by caesarean section: effect modification by family history of allergies – a population based cross-sectional study

Abstract

BackgroundStudies on the association of birth by caesarean section (C/S) and allergies have produced conflicting findings. Furthermore, evidence on whether this association may differ in those at risk of atopy is limited. This study aims to investigate the association of mode of delivery with asthma and atopic sensitization and the extent to which any effect is modified by family history of allergies.MethodsAsthma outcomes were assessed cross-sectionally in 2216 children at age 8 on the basis of parents’ responses to the ISAAC questionnaire whilst skin prick tests to eleven aeroallergens were also performed in a subgroup of 746 children. Adjusted odds ratios of asthma and atopy by mode of delivery were estimated in multivariable logistic models while evidence of effect modification was examined by introducing interaction terms in the models.ResultsAfter adjusting for potential confounders, children born by C/S appeared significantly more likely than those born vaginally to report ever wheezing (OR 1.36, 95% CI 1.07-1.71), asthma diagnosis (OR 1.41, 95% CI 1.09-1.83) and be atopic (OR 1.67, 95% CI 1.08-2.60). There was modest evidence that family history of allergies may modify the effect of C/S delivery on atopy (p for effect modification=0.06) but this was not the case for the asthma outcomes. Specifically, while more than a two-fold increase in the odds of being a topic was observed in children with a family history of allergies if born by C/S (OR 2.62, 95% CI 1.38-5.00), no association was observed in children without a family history of allergies (OR 1.16, 95% CI 0.64-2.11).ConclusionsBirth by C/S is associated with asthma and atopic sensitization in childhood. The association of C/S and atopy appears more pronounced in children with family history of allergies.

Childhood Health and Developmental Outcomes After Cesarean Birth in an Australian Cohort

“…Our goal was to test whether children born by cesarean delivery were more likely to have poor physical and socioemotional outcomes compared with children born vaginally. In line with previous research findings, 10,[12][13][14] we hypothesized that children born by cesarean delivery are more likely to experience asthma and allergies in their early years of life and have a higher BMI compared with their vaginally delivered peers.…”

“…[3][4][5][6] For example, studies have reported that children born by cesarean delivery may have increased rates of respiratory illness in their first year of life 5,7,8 and beyond, 9,10 and relationships have also been described with diabetes 11 and child overweight and obesity. 12,13 Notwithstanding these potential adverse associations, children born by cesarean delivery are usually healthy, and it is important to recognize that many factors influence child health other than mode of birth.…”

Influence of Intrinsic and Lifestyle Factors on the Development of IgE Sensitization

“…The German MAS-90 study reported decreased sensitization rates in vaccinated children [25], while in our cohort the few individuals ( n = 24) who were not vaccinated also demonstrated a sensitization rate >50%. Earlier studies, including higher numbers of participants born by cesarean, showed a significantly increased risk for atopy for this delivery mode [26]. A protective effect of breastfeeding on the development of allergic diseases has been suggested [27,28].…”

The gut microbiota and inflammatory noncommunicable diseases: Associations and potentials for gut microbiota therapies

“…Infants born by CS have a higher incidence of respiratory distress 38 and appear to be at higher risk for developing asthma and atopy 39 , obesity 40 and type 1 diabetes 41 . It has been hypothesized that delayed and aberrant intestinal colonization might contribute to this risk conferred by CS.…”