Spontaneous preterm birth following unintended hysterotomy extension during second‐stage labor cesarean delivery

Abstract Background Unintended hysterotomy extensions occur frequently during second‐stage cesarean delivery and may result in uterine and cervical tissue trauma. The impact of these extensions on adverse outcomes in subsequent pregnancies, including spontaneous preterm birth (sPTB), remains unknown. Objective We evaluated the association between unintended hysterotomy extension during second‐stage cesarean delivery and subsequent sPTB. Study design This was a retrospective cohort study of patients who underwent a primary cesarean delivery during the second stage of labor between March 2014 and August 2024 and had a subsequent delivery ≥14 weeks at a single academic tertiary care center in the Southeastern United States. Unintended hysterotomy extension was defined as any documented extension beyond the initial hysterotomy as recorded in the operative notes of the electronic health record. Patients who underwent cesareans with intentionally inverted T or J incisions were excluded. The primary outcome was the occurrence of sPTB (delivery