Impact of Pre-eclampsia and Emergency Cesarean Section without Labour on Bifidobacterium Levels in Infant Gut Microbiota

• Author / Creator

  Paraktoon, Maryam

• Background:
  Pre-eclampsia affects 8-10% of all pregnancies, resulting in significant maternal-fetal morbidity,
  including fetal distress, abnormal fetal heart rate, and placental abruption. These conditions also
  increase the risk of emergency cesarean delivery for pre-eclamptic women
  before a trial of labour.
  Furthermore, pre-eclamptic women face a higher likelihood of experiencing premature rupture of
  membranes (PROM), which has negative consequences for both mothers and infants. Recent
  findings have indicated that there are distinct gut microbiota changes in groups with pre-eclampsia
  compared to healthy control groups, thus confirming the potential link between dysbiosis of the
  gut microbiota and the occurrence of pre-eclampsia. However, there is lack of knowledge
  regarding gut microbiota alterations in infants born to pre-eclamptic mothers. Since critical gut
  microbiota and immune system interactions can be affected by microbial dysbiosis resulting from
  maternal health conditions, cesarean birth, and other birth events, the current study aimed to
  investigate the association between pre-eclampsia and the levels of key microbiota,
  Bifidobacterium, in the infant gut at 3 months of age. Additionally, this study aimed to explore
  whether this association is independent of emergency cesarean delivery without labour and
  premature rupture of membranes (PROM), as well as to determine if these factors mediate the
  observed association.
  Methods:
  This was a prospective cohort study utilizing data on 1429 mother-infant pairs, longitudinally from
  the Canadian Healthy Infant Longitudinal Development (CHILD) population-based birth cohort. Data on delivery mode, pre-eclampsia, PROM, breastfeeding status, maternal pre-pregnancy BMI
  and other maternal and infant covariates were collected from hospital records or standard maternal
  questionnaires. Infant fecal samples, collected at 3-4 months of age, were profiled by qPCR for
  levels of total Bifidobacterium. Fisher's exact tests was employed to assess crude unadjusted
  associations between maternal and infant characteristics with pre-eclampsia, emergency cesarean
  section without labour, and Bifidobacterium levels. To enhance data normality, Bifidobacterium
  values underwent Box-Cox transformation before logistic regression analysis. Simple and multiple
  logistic regressions (using STATA version 17) were utilized to identify the impact of preeclampsia on Bifidobacterium levels in the infant gut microbiome, while considering adjustments
  for potential confounding variables as suggested by the Directed Acyclic Graph (DAG).
  Additionally, mediation analyses were conducted using the Hayes PROCESS v3.5 macro in SPSS
  (version 26, SPSS Inc., Chicago, IL, USA) to examine whether emergency cesarean delivery
  without labour and premature rupture of membranes (PROM) are in the pathway between preeclampsia and Bifidobacterium levels in infant.
  Results:
  In our study, we observed a significant inverse association between pre-eclampsia and
  Bifidobacterium levels in the gut microbiota of infants at 3 months of age in the crude logistic
  analysis (βc: -1.48, 95% CI: -2.9, -0.05, p < 0.05). However, after adjusting for potential
  confounding variables, this association lost its significance (βa: 0.31, 95% CI: -1.28, 1.90, p >
  0.05). Furthermore, our investigation into the mediation process using simple and sequential
  analyses did not fully support the hypothesis that emergency cesarean delivery without labour and
  premature rupture of membranes (PROM) act as mediators between pre-eclampsia and
  Bifidobacterium levels in the infant gut microbiota. However, when examining the role of birth. mode as a mediator, our mediation analyses revealed a significant inverse association between
  cesarean section (elective and emergency CS with and without labour) and Bifidobacterium levels
  in the infant gut microbiota at 3 months of age. Additionally, we found similar results in the second
  mediation model, indicating that rupture of membranes has an inverse impact on Bifidobacterium
  levels in the infant gut.
  Conclusion:
  To summarize, our findings indicate that infants born to mothers with pre-eclampsia had decreased
  levels of Bifidobacterium in their gut at 3 months of age. However, it is important to note that the
  statistical significance of this association was not maintained after adjusting for potential
  confounding variables due to the limited sample size. Our study also revealed that cesarean section
  including elective and emergency CS with and without labour, had an inverse influence on
  Bifidobacterium levels, aligning with previous research findings. Furthermore, we observed an
  inverse association between rupture of membranes and Bifidobacterium levels, which warrants
  further investigation.

• Subjects / Keywords

  • Pre-eclampsia
  • Emergency Cesarean Section without Labour
  • Infant Gut Microbiota
  • Bifidobacterium

• Graduation date

  Fall 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-6se7-c967

• 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.