Background: Intrapartum antibiotic prophylaxis (IAP) is administered to the majority of pregnant women who test positive for Group B Streptococcus (GBS) to prevent early-onset GBS infections. The impact of IAP on the infant gut microbiome and subsequent impact on immune system development and potential for obesity remain a critical concern. The objective of this study is to synthesise the available evidence of IAP exposure on autoimmune diseases and obesity prevalence in childhood and microbial diversity in babies.
Methods: Several databases were searched from inception until 1 May 2024 for observational studies investigating the effect of IAP on autoimmune diseases, obesity, and gut microbiota. For autoimmune diseases, adjusted relative risk ratios (RRs) and corresponding 95% confidence intervals (CIs) and for BMI, BMI z-score and gut microbiome diversity, mean difference (MD) and corresponding 95% CIs were performed. Pre-specified subgroups analyses were also performed to investigate the potential differential effect of IAP on each outcome
Results: 19 studies were eligible of which 16 were included in the meta-analysis (autoimmune disease, n=5; child obesity, n=4; gut microbiome biodiversity, n=7). On meta-analysis, IAP exposure was associated with a higher mean BMI (MD= 0.05; 95% CI: 0.03–0.06, P < 0.05, k=2) and higher BMI z-score (MD= 0.18; 95% CI: 0.02–0.35, P < 0.05, k=3 studies). IAP exposure was associated with increased risk of autoimmune disease (RR= 2.21; 95% CI: 1.00–4.90, P < 0.0001, k=5). IAP exposure was not associated with changes in microbiome diversity among infants (MD= -0.09; 95% CI: -.20–0.02, k=7).
Conclusion: IAP exposure significantly increases the risk of autoimmune disease and is associated with higher mean BMI and BMI z-score in childhood.