Risk Factors for Unintended Dural Puncture in Obstetric Patients: A Retrospective Cohort Study.

Background: Unintended dural puncture (UDP) is one of the main risks of epidural analgesia, with a reported incidence of approximately 1.5% among the obstetric population. UDP is associated with maternal adverse outcomes, with the most frequent adverse outcome being postdural puncture headache (PDPH).