Cesarean section without medical indication and risk of childhood asthma, and attenuation by breastfeeding

Shuyuan Chu; Qian Chen; Yan Chen; Yixiao Bao; Min Wu; Jun Zhang

doi:10.1371/journal.pone.0184920

Cesarean section without medical indication and risk of childhood asthma, and attenuation by breastfeeding

PLoS One. 2017 Sep 18;12(9):e0184920. doi: 10.1371/journal.pone.0184920. eCollection 2017.

Authors

Shuyuan Chu^{1

2}, Qian Chen², Yan Chen^{2

3}, Yixiao Bao³, Min Wu⁴, Jun Zhang^{2

5}

Affiliations

¹ The Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, China.
² MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
³ Department of Pediatrics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
⁴ Department of Traditional Chinese Medicine, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
⁵ School of Public Health, Guilin Medical University, Guilin, China.

Abstract

Background: Previous studies suggest that caesarean section (CS) may increase the risk of asthma in children, but none of them could preclude potential confounding effects of underlying medical indications for CS. We aim to assess the association between CS itself (without medical indications) and risk of childhood asthma.

Methods: We conducted a hospital-based case-control study on childhood asthma with 573 cases and 812 controls in Shanghai. Unconditional logistic regression models in SAS were employed to control for potential confounders.

Results: Our study found that CS without medical indication was significantly associated with elevated asthma risk (adjusted OR = 1.58 [95% CI 1.17-2.13]). However, this risk was attenuated in children fed by exclusive breastfeeding in the first six months after birth (adjusted OR = 1.39 [95% CI 0.92-2.10]). In contrast, the risk was more prominent in children with non-exclusive breastfeeding or bottle feeding (adjusted OR = 1.91 [95% CI 1.22-2.99]).

Conclusions: CS without medical indication was associated with an increased risk of childhood asthma. Exclusive breastfeeding in infancy may attenuate this risk.

MeSH terms

Adult
Asthma* / epidemiology
Asthma* / etiology
Asthma* / prevention & control
Breast Feeding*
Case-Control Studies
Cesarean Section*
Child
Child, Preschool
Female
Humans
Male
Risk Factors

Grants and funding

The work was supported by the National Natural Science Foundation of China (81273091, 81530086); Shanghai Municipal Health and Family Planning Commission (GWIV-26; 15GWZK0401); Shanghai Science and Technology Commission (14XD1403300). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.