Gastric Volume and Fasting Duration in Pregnant Women (PREG-GAS)

Comparison of Gastric Volume Measured by Ultrasonography According to Preoperative Fasting Duration in Pregnant Women Undergoing Elective Cesarean Section and Evaluation of Influencing Factors

This prospective observational study aimed to evaluate the effect of preoperative fasting duration on gastric volume and antral visibility in pregnant women undergoing elective cesarean section. Patients were divided into two groups according to fasting duration (6-8 hours and 8-10 hours), and preoperative gastric ultrasonography was performed to assess antral cross-sectional area and gastric volume.

Additionally, the study investigated the relationship between gastric ultrasound findings and postoperative complications such as nausea and vomiting. The influence of demographic and clinical variables, including age, body mass index, ASA score, and fetal characteristics, on gastric volume was also evaluated.

Study Overview

• Status: Completed
• Conditions: Pregnancy; Gastric Volume; Postoperative Nausea and Vomit; Ceserean Section

Detailed Description

This prospective observational study was conducted to evaluate the effect of preoperative fasting duration on gastric volume and antral visibility in pregnant women undergoing elective cesarean section. A total of 90 pregnant women were included in the study and divided into two groups based on fasting duration (6-8 hours and 8-10 hours).

Preoperative gastric ultrasonography was performed in all patients to measure antral cross-sectional area and estimate gastric volume. Gastric content was also assessed using antral grading. Demographic and clinical data including age, body mass index, ASA physical status, comorbidities, and fetal characteristics were recorded.

Postoperative outcomes such as nausea, vomiting, and aspiration were evaluated and their relationship with gastric ultrasound findings was analyzed. Additionally, factors affecting gastric volume were assessed using statistical models.

The results of this study may contribute to improved perioperative risk stratification and individualized assessment of aspiration risk in obstetric anesthesia, and may help optimize preoperative fasting protocols.

• Study Type: Observational
• Enrollment (Actual): 90

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Kartal, Istanbul, Turkey (Türkiye), 34865
      • Kartal Dr. Lütfi Kırdar City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women aged 18-45 years with term gestation (37-40 weeks), ASA physical status II-III, and body mass index below 35 kg/m² who were scheduled for elective cesarean section under spinal anesthesia at a tertiary care hospital were included in this study.

Description

Inclusion Criteria:

• Pregnant women aged 18-45 years Gestational age between 37-40 weeks Scheduled for elective cesarean section ASA physical status II-III Body mass index (BMI) < 35 kg/m² Undergoing spinal anesthesia

Exclusion Criteria:

• BMI ≥ 35 kg/m² Emergency cesarean section Known gastrointestinal disease (e.g., gastroesophageal reflux disease) Use of medications affecting gastric motility History of gastric surgery Presence of infiltrative diseases (e.g., scleroderma, amyloidosis) Use of antiemetic drugs within 24 hours before surgery Severe hypertension during pregnancy (systolic >160 mmHg or diastolic >110 mmHg) Multiple pregnancy Patients who refused to participate

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort
grup 1 label 6-8 Hours Fasting
grup 1 label 6-8 Hours Fasting. grup 2 label8-10 Hours Fasting; Grup 1: Pregnant women undergoing elective cesarean section with a preoperative fasting duration of 6-8 hours. Grup 2: Pregnant women undergoing elective cesarean section with a preoperative fasting duration of 8-10 hours.
6-8 Hours Fasting; Pregnant women undergoing elective cesarean section with a preoperative fasting duration of 6-8 hours.
8-10 Hours Fasting; Pregnant women undergoing elective cesarean section with a preoperative fasting duration of 8-10 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastric Volume Measured by Ultrasonography	Preoperative gastric volume measured using gastric ultrasonography in pregnant women undergoing elective cesarean section, and comparison between different fasting duration groups (6-8 hours vs 8-10 hours).	Preoperative period (before anesthesia induction)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Antral Cross-Sectional Area	Measurement of gastric antral cross-sectional area using ultrasonography and comparison between fasting duration groups.	Preoperative period

Collaborators and Investigators

• Sponsor: Dr. Lutfi Kirdar Kartal Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2024
• Primary Completion (Actual): June 1, 2025
• Study Completion (Actual): June 1, 2025

Study Registration Dates

• First Submitted: March 31, 2026
• First Submitted That Met QC Criteria: March 31, 2026
• First Posted (Actual): April 7, 2026

Study Record Updates

• Last Update Posted (Actual): April 7, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Cesarean section; gastric ultrasound; obstetric anesthesia; aspiration risk; gastric volume; fasting duration; antral cross-sectional area
• Additional Relevant MeSH Terms: Postoperative Complications; Pathologic Processes; Signs and Symptoms, Digestive; Nausea; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Vomiting; Postoperative Nausea and Vomiting
• Other Study ID Numbers: KAD-FR-42-2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No