Study Type: Observational, prospective, multicenter comparative study

Primary Purpose: The goal of this study is to evaluate whether grape juice can serve as an effective alternative to the standard 50g glucola drink for gestational diabetes screening in pregnant individuals at 24-28 weeks of gestation.

Main Questions:

Can an alternative glucose-loading drink (grape juice) provide comparable blood glucose measurements to the standard GCT? Does grape juice improve patient satisfaction and compliance with gestational diabetes screening?

Comparison Group:

Researchers will compare the standard GCT (50g glucola drink) with the alternative GCT (500 ml grape juice containing 50g sugar). Each participant will undergo both tests, serving as her own control, to assess differences in glucose measurements and patient preferences.

Participant Tasks:

Participants will:

- Undergo two glucose challenge tests (GCT): Standard GCT (50g glucola) at their health maintenance organization (HMO) or hospital.

Alternative GCT (500 ml grape juice) during a scheduled visit or hospitalization.

• Have blood drawn one hour after each test for glucose measurement.
• Complete a questionnaire assessing satisfaction and preference between the two methods.
• Provide follow-up information if they require additional testing (e.g., 100g OGTT).

Study Type: Prospective, observational, multicenter comparative study Primary Purpose: To evaluate whether grape juice can serve as an effective alternative to the standard 50g glucola drink for gestational diabetes screening, with the goal of improving patient compliance and satisfaction.

Participant Population: Pregnant individuals at 24-28 weeks of gestation, undergoing routine glucose challenge testing (GCT). Participants will be recruited from Maternal-Fetal Medicine (MFM) clinics, prenatal maternal wards, and social media outreach.

Main Research Questions:

Can an alternative glucose-loading drink (grape juice) provide comparable blood glucose measurements to the standard GCT? Does grape juice improve patient satisfaction and compliance with gestational diabetes screening?

Study Design & Methods:

Participants: Each participant will undergo both the standard GCT and an alternative GCT using 500 ml of grape juice (containing 50g of sugar).

Control Group: Each participant serves as her own control by completing both tests in a randomized order.

Blood Glucose Measurement: A blood sample will be drawn one hour after ingestion of each drink to compare glucose levels.

Follow-up: If necessary, follow-up phone calls will be conducted to collect results from the standard GCT performed at external clinics.

Outcome Measures:

Primary Outcomes:

Mean difference in blood glucose levels between the standard and alternative GCT.

Proportion of patients with a positive screening result (≥140 mg/dL) for both methods.

Sensitivity, specificity, and predictive values of the alternative GCT compared to the standard test.

Agreement between the two methods using Bland-Altman analysis.

Secondary Outcomes:

Patient satisfaction with both screening methods (measured via a Likert scale). Participant preference between grape juice and glucola. Incidence of adverse events (e.g., nausea, dizziness).

Statistical Analysis:

Pearson's correlation and paired t-tests will assess the agreement between glucose measurements.

ROC analysis will determine the diagnostic performance of the alternative test. Bland-Altman plots will evaluate bias and agreement between the two methods.

Sample Size Calculation:

A minimum of 120 participants is required to detect a clinically significant difference, accounting for attrition.

Recruitment Strategy:

Multicenter Approach: Enrollment from two major hospitals (Bnai Zion and Poria).

Social Media Outreach: Targeted campaigns will inform and recruit participants. Incentives: Participants will receive a complimentary MFM consultation and fetal ultrasound.

Significance:

If grape juice proves to be a viable alternative to the standard GCT, it could improve patient compliance, enhance screening participation, and minimize the discomfort associated with traditional glucose testing.

Inclusion Criteria:

• Inclusion Criteria:

Pregnant individuals scheduled for routine GCT at 24-28 weeks. Well-dated pregnancy (confirmed first-trimester ultrasound). Willingness to comply with study protocol.

Exclusion Criteria:

High-risk individuals requiring direct 100g OGTT (e.g., prior GDM, BMI >40, PCOS).

Intolerance to the alternative drink. Gastrointestinal conditions affecting glucose absorption such as active bowel disiease.

Recent corticosteroid administration for fetal lung maturity after standard GCT.

De identified individual participant data collected in this study will not be shared outside the study team.