Epidural Blood Patch on the Resolution of Postdural Puncture Headache (PDPH)

Inclusion Criteria: * Obstetric patients aged 18 or more years * Post-dural puncture headache (PDPH) after a confirmed or likely unintentional dural puncture with an epidural needle. PDPH is defined as " A headache with clear postural characteristics (onset or significant exacerbation when erect and relieved or significantly diminished by lying flat). The diagnosis is supported by distribution in the frontal or occipital region, with associated neck ache." * Medically suitable for and have consented to epidural blood patch (EBP) for treatment of PDPH Exclusion Criteria: * Previous epidural blood patch (EBP) related to the same unintentionl dural puncture (including prophylactic EBP) * EBP to be performed more than 5 days after the unintentional dural puncture. * History of significant low or radicular back pain (requiring treatment) during pregnancy * Women in whom a further dural puncture occurs at the time of epidural needle insertion for the EBP * Diagnosis other than PDPH subsequently confirmed.