University of Oulu

Pyrhönen, K, Kulmala, P. Delivery mode and the incidence of atopic sensitization and food allergy in a Finnish child population. Pediatr Allergy Immunol. 2021; 33:e13584.

Delivery mode and the incidence of atopic sensitization and food allergy in a Finnish child population

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Author: Pyrhönen, Kaisa1,2; Kulmala, Petri2,3
Organizations: 1Center for Life Course Health Research, University of Oulu, Oulu, Finland
2PEDEGO Research Unit and MRC Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
3Biomedicine Research Unit, Medical Microbiology and Immunology, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
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Language: English
Published: John Wiley & Sons, 2022
Publish Date: 2022-03-07


Background: Caesarean section (CS) has been associated with an increased risk of subsequent atopic diseases, particularly asthma and respiratory allergies, but controversial findings have also been reported. Our aim was to clarify the association between the delivery mode and longitudinal (atopic) outcomes.

Methods: The target population was identified from the population register and comprised all children born between 2001 and 2006 and living in the province of South Karelia, Finland (N = 5564). The information on the delivery mode was available for 5552 children from the Finnish Medical Birth Register. Results of allergy tests (skin prick tests, specific IgE and open food challenges, OFCs) were collected from patient records of all healthcare units in the area.

Results: By 12 years of age, the cumulative incidence of atopic sensitization was 15% for those born by normal vaginal delivery (VD), 20% (adjusted RR 1.28; 95% CI 0.99–1.65) by assisted VD, 20% (adjusted RR 1.28; 95% CI 1.02–1.61) by elective CS and 20% (adjusted RR 1.24; 95% CI 0.99–1.56) by others, for example emergency CS. Among the offspring of mothers without atopic diseases, the incidence of food allergy (positive OFC) was 6% for those born by elective CS and 2% for those born by normal VD (adjusted RR 2.41; 95% CI 1.19–4.88), while the respective incidences were 5% and 6% (adjusted RR 0.82; 95% CI 0.33–2.06) among the offspring of mothers with atopic diseases.

Conclusion: By adolescence, the cumulative incidences of atopic sensitization was highest among those born by assisted VD or CS. The incidence of food allergy was highest among those born by elective CS among the offspring of mothers without atopic diseases.

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Series: Pediatric allergy and immunology
ISSN: 0905-6157
ISSN-E: 1399-3038
ISSN-L: 0905-6157
Volume: 33
Issue: 1
Article number: e13584
DOI: 10.1111/pai.13584
Type of Publication: A1 Journal article – refereed
Field of Science: 3123 Gynaecology and paediatrics
3121 General medicine, internal medicine and other clinical medicine
Funding: The data collection was funded by the Social Insurance Institution of Finland and partly by EVO grants from the hospital districts of South Karelia and Northern Ostrobothnia, by Lappeenranta City Council, and personal grants to the principal investigator from the Finnish Cultural Foundation, South Karelia Regional Fund, the Viipuri Tuberculosis Foundation, the Väinö and Laina Kivi Foundation, the Tyyni Tani Foundation, Kymenlaakson Terveyden Turva r.y., the Allergy Foundation and the Medical Society of South Karelia. The work of the principal investigator (KP) was funded from 2016 to 2018 by the Finnish Cultural Foundation (Pekka and Jukka-Pekka Lylykari’s Fund) and South Karelia Regional Fund (Lauri and Lahja Hotinen Fund) and from 2019 by the Northern Ostrobothnia Hospital District, the Finnish Pediatric Research Foundation, the Viipuri Tuberculosis Foundation and the Finnish Medical Association. The work of the second author (PK) was supported by the research grants from the Alma and K.A. Snellman Foundation, the Finnish Medical Association and the Finnish Pediatric Research Foundation. None of the funding organizations was involved in the design or execution of the study
Copyright information: © 2021 The Authors. Pediatric Allergy and Immunology published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.