Minimally Invasive Lumbar Aneasthesia Used for Cesarean Section

Traditional group patients will receive cutting type 22 gauge needles, while minimally invasive group patients will receive pen type 27 gauge needles.Patients will be blinded to the intervention allocations. Spinal anesthesia will be performed with a standardized technique. Lumbar puncture will be performed through an interspace (L3-4 or L2-3) with patients in a lateral decubitus position. After free flow of cerebrospinal fluid through the needle tip be verified, 2ml ropivacaine will be injected. We will record puncture situation, anesthesia plane and measure post-dural puncture headache, post-operative back pain and epidural hematoma.