Duration of labour and its impact on the infant gut microbial composition in the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort

  • Author / Creator
    Rai, Usha
  • Background: Balanced development of infant gut microbiota is pivotal for immune maturation and energy homeostasis, and infant gut dysbiosis is associated with increased risk of childhood atopy, allergy and excess weight gain. Shifts in abundance of gut Bacteroidetes and Firmicutes during infancy, along with reduction of probiotic organisms such as Bifidobacterium and Lactobacillus, has been linked to higher risk of childhood allergy and excess adiposity. Evidence shows that mode of delivery profoundly affects infant gut microbiota development. Yet, information on effect of duration of labour, an inherent component of natural birth, on microbial colonization of infant gut is scarce. Objectives: To examine the influence of duration of labour on the infant gut microbiota composition and diversity at 3 to 4 months of age. Methods: A subset of 1028 infants from the Edmonton, Winnipeg and Vancouver sites of the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort were included in the study. Data on duration of labour, other birth characteristics and maternal pre-pregnancy body mass index (BMI) was obtained from hospital birth charts. Infant gut microbiota was characterized using Illumina MiSeq 16S rRNA gene sequencing of fecal samples collected at 3-4 months of age. Microbial relative abundance, Chao1 richness and Shannon diversity were determined. Results: Longer duration of labour was associated with reduced gut colonization with genera Bifidobacterium and Lactobacillus in infants at 3-4 months of age. Odds of colonization with Bifidobacterium reduced significantly with active first stage longer than 13 hours [aOR = 0.56 (95%CI = 0.34-0.95); p =0.030] and second stage longer than 2 hours [aOR = 0.48 (95%CI = 0.32- 0.73); p =0.001]. Likewise, odds of colonization with Lactobacillus also reduced with active first stage longer than 13 hours [aOR = 0.53 (95%CI = 0.30-0.95); p=0.032] and second stage longer than 2 hours [aOR = 0.63 (95%CI = 0.41-0.98); p =0.041]. Infants born to obese mothers showed more severe reduction in Bifidobacterium and Lactobacillus colonization in association with longer labour durations. In addition, Veillionellaceae tended to increase with longer labour in infants of normal weight mothers where as an inverse trend was observed among infants of obese mothers. Conclusion: The findings provide evidence of infant gut microbiota dysbiosis associated with longer durations of labour. Elevation of maternal pre-pregnancy BMI further accentuates the observed changes in infant gut microbial profile. The long-term consequences of these compositional changes on immune maturation and metabolic homeostasis and risk of childhood allergy and obesity requires further study.

  • Subjects / Keywords
  • Graduation date
    Spring 2018
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.