Spinal anesthesia is commonly used for cesarean section and provides effective anesthesia with rapid onset. However, the spread of spinal anesthesia may vary among pregnant women due to physiological and anatomical changes during pregnancy. Increased intra-abdominal pressure and abdominal circumference may influence cerebrospinal fluid dynamics and affect the level of sensory block achieved after spinal anesthesia.

This prospective observational study aims to evaluate the relationship between intra-abdominal pressure, abdominal circumference, and the maximum sensory block level following spinal anesthesia in pregnant women undergoing cesarean section. Intra-abdominal pressure and abdominal circumference will be measured before surgery, and sensory block levels and hemodynamic parameters will be assessed after spinal anesthesia. The findings of this study may help to better understand factors affecting spinal block spread in pregnant patients.

Inclusion Criteria:

• Pregnant women aged 18-40 years
• Scheduled for elective cesarean section at Kütahya City Hospital
• Planned spinal anesthesia
• ASA physical status II-III
• Provided written informed consent

Exclusion Criteria:

• Refusal to participate in the study
• Emergency cesarean section
• Preeclampsia or other hypertensive disorders of pregnancy
• Onset of labor or premature rupture of membranes
• Clinical conditions affecting intra-abdominal pressure, including peripheral edema or ascites
• Height <140 cm or >180 cm
• Body mass index < 40 kg/m²
• Spinal deformity or history of spinal surgery
• Contraindications to neuraxial anesthesia
• Known allergy to bupivacaine
• Requirement for additional surgical procedures other than cesarean section
• Conditions contraindicating or interfering with intra-abdominal pressure measurement, including active or previous postdural puncture headache, neurogenic bladder, hematuria, or incidental abdominal mass

This study includes pregnant women aged 18-40 years who were scheduled for elective cesarean section under spinal anesthesia at the Department of Obstetrics and Gynecology, Kütahya City Hospital. Eligible participants belonged to ASA physical status II-III and provided informed consent. The study population represents a clinically stable obstetric cohort undergoing elective cesarean delivery, without conditions known to significantly alter intra-abdominal pressure or spinal anesthesia characteristics.