Interleukin-1 receptor antagonist, mode of analgesia and risk of Caesarean delivery after onset of labour: a Mendelian randomisation analysis

Background Lower circulating levels of the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1ra) are associated with intrapartum inflammation and epidural analgesia-related maternal fever, both of which increase the rate of obstetric interventions. We hypothesised that genetic variants determining IL-1ra levels would be associated with Caesarean delivery rates after the onset of labour. Methods We performed Mendelian...