GRAPE-GDM Prospective Comperative Trial - Grape Juice as a Replacement Drink for Gestational Diabetes Screening

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).