OBJECTIVE: To determine whether the use of an intrauterine catheter during labor is related to the occurrence of infection in mother or newborn during labor and up to 3 weeks postpartum. METHODS: We performed a follow-up study of 1435 women who participated in a previously published multicentre randomized controlled trial in the Netherlands that assigned women in whom labor was induced or augmented with intravenous oxytocin to internal or external tocodynamometry. In the present post hoc analysis, we assessed the risk for infection, defined as a composite measure of any clinical sign of infection, treatment with antibiotics or sepsis during labor or in the postpartum period up to 3 weeks in mother or newborn. RESULTS: There were 64 cases with indication of infection in the intrauterine catheter group (8.8%) versus 74 cases in the external monitoring group (10.4%). Relative risk: 0.91, 95% confidence interval: 0.77-1.1, and p: 0.33. CONCLUSION: Use of an intrauterine catheter during labor does not increase the risk of infection. ; Karlijn Van Halem, Jannet J. H. Bakker, Corine J. Verhoeven, Dimitri N. M. Papatsonis, Elisabeth D. Van Oudgaarden, Petra Janssen, Kitty W. Bloemenkamp, Ben Willem J. Mol & Joris A. M. Van Der Post