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

March 31, 2026 updated by: Dr. Fırat Mavi, Dr. Lutfi Kirdar Kartal Training and Research Hospital

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

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

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

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

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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
Time Frame: Preoperative period (before anesthesia induction)
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
Time Frame: Preoperative period
Measurement of gastric antral cross-sectional area using ultrasonography and comparison between fasting duration groups.
Preoperative period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

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

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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