Abdominal Circumference Measure in Caesarian Section

The goal of this observational study is to evaluate preoperative measures of abdominal circumference in patients admitted for a cesarean section. The main questions it aims to answer are: * Can preoperative abdominal circumference predict patients with difficult spinal anesthesia * Can preoperative abdominal circumference predict the occurrence of maternal hypotension during cesarean section Participants will be examined preoperatively in terms of visibility and palpation of spinous processes, abdominal circumference will be measured in the supine and sitting positions with other clinical parameters. Spinal anesthesia will be performed by the same experienced anesthesiologist with a standardized procedure. The number of skin punctures, needle reorientations, traumatic Cerebrospinal fluid, need for a paramedian approach or failure will be recorded. Maternal blood pressure and vasopressor requirements will also be monitored.