Gastric Ultrasound After Clear Fluid Intake in Diabetic and Non-Diabetic Pregnant Women

Effect of Preoperative Clear Fluid Intake on Gastric Volume in Diabetic and Non-Diabetic Pregnant Women Assessed by Gastric Ultrasonography

Pulmonary aspiration of gastric contents during anesthesia is a serious perioperative complication associated with significant morbidity and mortality. Pregnant patients are at increased risk of aspiration due to physiological changes such as delayed gastric emptying and increased intra-abdominal pressure. In addition, diabetes may impair gastric motility because of autonomic neuropathy, potentially leading to gastroparesis and increased gastric residual volume.

Current fasting guidelines allow the intake of clear fluids up to two hours before anesthesia. However, the effect of preoperative oral clear fluid intake on gastric volume in diabetic pregnant patients remains unclear.

This prospective observational study aims to compare gastric volume measured by gastric ultrasonography in diabetic and non-diabetic pregnant women undergoing elective cesarean delivery. All participants will receive 200 ml of water two hours before surgery. Gastric ultrasonography will be performed before fluid intake and two hours after intake to evaluate gastric volume and gastric content.

The results of this study may help improve the assessment of aspiration risk and guide perioperative fasting recommendations in pregnant patients, particularly those with diabetes.

Study Overview

• Status: Recruiting
• Conditions: Pregnancy; Pulmonary Aspiration; Diabetes in Pregnancy

Detailed Description

Pulmonary aspiration of gastric contents is one of the most feared complications of obstetric anesthesia and may lead to severe morbidity and mortality. Pregnancy is associated with physiological changes such as delayed gastric emptying, increased intra-abdominal pressure, and gastroesophageal reflux, all of which may increase the risk of aspiration during anesthesia. Diabetes mellitus may further affect gastric motility due to autonomic neuropathy, potentially leading to gastroparesis and increased gastric residual volume.

Preoperative fasting guidelines from major anesthesia societies recommend that patients may consume clear fluids up to two hours before anesthesia. However, the effect of preoperative oral clear fluid intake on gastric volume in diabetic pregnant patients remains controversial.

This single-center prospective observational study will be conducted in pregnant women scheduled for elective cesarean delivery. A total of 70 participants will be included and divided into two groups: diabetic pregnant women and non-diabetic pregnant women. All participants will receive 200 ml of water two hours before surgery according to standard fasting guidelines.

Gastric ultrasonography will be performed before fluid intake and two hours after fluid intake. The gastric antrum will be identified using anatomical landmarks including the left lobe of the liver, pancreas, aorta, and inferior vena cava. Measurements will be obtained in both the semi-recumbent and right lateral decubitus positions.

The gastric antral cross-sectional area will be calculated using the formula:

CSA = (D1 × D2 × π) / 4.

Gastric volume will be estimated using the Roukhomovsky equation. In addition to quantitative measurements, qualitative assessment of gastric contents will be performed using the Perlas grading system.

The primary objective of the study is to compare gastric volume between diabetic and non-diabetic pregnant women after preoperative clear fluid intake. Secondary objectives include qualitative evaluation of gastric contents and assessment of aspiration risk defined as gastric volume greater than 1.5 ml/kg.

• Study Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: İrem Dinçer, MD; Phone Number: +905333641512; Email: iremdincer97@gmail.com

Study Locations

• Turkey (Türkiye)
  • Ankara
    • Ankara, Ankara, Turkey (Türkiye), 06800
      • Recruiting
      • Ankara Bilkent City Hospital
      • Contact: İrem Dinçer, MD; Phone Number: +905333641512; Email: iremdincer97@gmail.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women aged 18-40 years undergoing elective cesarean section under spinal anesthesia at a tertiary care hospital. The study includes both diabetic and non-diabetic pregnant women who meet the eligibility criteria and provide informed consent.

Description

Inclusion Criteria:

• Pregnant women aged 18-40 years
• Scheduled for elective cesarean section under spinal anesthesia
• Singleton pregnancy
• ASA physical status II
• Patients who provide written informed consent

Exclusion Criteria:

• Refusal to participate in the study
• Contraindication to spinal anesthesia
• Known allergy to study medications
• Multiple pregnancy
• Severe systemic disease (ASA III or higher)
• Pre-existing neurological disease
• Infection at the spinal puncture site

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Diabetic Pregnant Women; Pregnant women with diet-controlled diabetes undergoing elective cesarean delivery. Participants will receive 200 ml of water two hours before surgery and gastric ultrasonography will be performed before and after fluid intake.
Non-Diabetic Pregnant Women; Pregnant women without diabetes undergoing elective cesarean delivery. Participants will receive 200 ml of water two hours before surgery and gastric ultrasonography will be performed before and after fluid intake.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastric Volume Measured by Ultrasonography	Gastric antral cross-sectional area will be measured using gastric ultrasonography and gastric volume will be calculated using the Roukhomovsky formula. Gastric volume will be compared between diabetic and non-diabetic pregnant women undergoing elective cesarean delivery.	Before oral clear fluid intake and two hours after fluid intake before anesthesia

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Qualitative Assessment of Gastric Contents	Gastric contents will be qualitatively assessed using the Perlas grading system (Grade 0-2) in both supine and right lateral decubitus positions.	Before oral clear fluid intake and two hours after fluid intake
Aspiration Risk Based on Gastric Volume	Aspiration risk will be assessed using the threshold of gastric volume greater than 1.5 ml/kg.	Two hours after oral clear fluid intake before anesthesia

Collaborators and Investigators

• Sponsor: Ankara City Hospital Bilkent

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: March 16, 2026
• First Submitted That Met QC Criteria: March 16, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cesarean Delivery; Pregnant Women; Gastric Volume; Gastric Ultrasound; Preoperative Fasting; Aspiration Risk
• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolic Diseases; Pregnancy Complications; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes, Gestational
• Other Study ID Numbers: IDGASTRICUSG2025

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