Interleukin-1 Receptor Antagonist, Mode of Analgesia and Risk of Cesarean Delivery After Onset of Labor: A Mendelian Randomization Analysis

( Br J Anaesth . 2022;128:89–97) Inflammation during labor can cause a host of complications that can in turn lead to emergency cesarean delivery due to increased risks to both mother and child. The body has natural responses to inflammation, one of which is the release of an anti-inflammatory cytokine, an interleukin-1 receptor antagonist (IL-1ra). The gene that encodes the expression of IL-1ra has 2 upstream alleles that increase mRNA expression and IL-1ra concentration. Previously in similar situations where genes have been identified and associated, Mendelian randomization techniques have been able to show causal relationships between the genes and observable outcomes.