The diagnosis of diabetes in pregnancy is clinically important for the baby (fetus) and the mother . The American Diabetes Association (ADA) article entitled “Classification and Diagnosis of Diabetes: Standards of Care in Diabetes-2023” provides a full discussion of diabetes and pregnancy . A variety of criteria for the diagnosis of gestational diabetes mellitus (GDM) are available and the selection of the optimal criteria is highly debated .
Nausea/vomiting are common complaints of pregnant women who have undergone gestational diabetes mellitus (GDM) testing . The causes of such gastrointestinal upset (and lack of palatability) of the commonly used glucose beverages include their extreme sweetness, their high osmolality, and the tendency of patients to swallow the beverage rapidly. Nausea, that is commonly observed in the first trimester of pregnancy (i.e., “morning sickness”), has usually significantly dissipated by the time of GDM screening at 24 to 28 weeks .
Keeping in mind the importance and controversy concerning the diagnosis of GDM, with the recent development of the “Fresh Test” as a glucose source for GDM testing in pregnancy , new discussions have arisen as to what glucose sources are “appropriate” for such testing.
Fresh Test is advertised as an “organic mint+lemonade glucose beverage” containing “only three natural ingredients” [crystallized lemon (citric acid, lemon oil, lemon juice) and organic peppermint leaf extract) and non-GMO (genetically modified organism) dextrose derived from corn or tapioca]. The products are vegan and no artificial colors or flavors are used in the manufacturing process. The product is sold as packs of 50g of glucose, 75g of glucose and 100g of glucose that are each then mixed with 10 ounces (~300 mL) of cold water. The web states: “.. (the) product (is) delicious and well tolerated … The Fresh Test™ is validated and audited to ensure exact amounts of 50-grams, 75-grams and 100-grams of glucose.” Lab Corp allows the use of Fresh Test products . No data have been presented by the manufacturer that Fresh Test is equivalent to traditional glucose beverages that are often referred to as
“glucolas.” This being said, the WHO does not require that glucose beverages be evaluated for their equipoise.
Candy for GDM screening
Various candies have been proposed as glucose sources for GDM screening . Because jelly beans are not uniform in their weight or sugar content, and the sugar or sugars are not identified, the use of jelly beans for a 50g GDM screening test cannot be recommended. Similar to the argument concerning jelly beans (and only limited data), Twizzlers should not be recommended for use in the 50g screening .
Laboratorians should be aware that oral glucose tolerance tests in pregnancy are not well tolerated . If jelly beans and Twizzlers are not recommended for GDM screening, and there is no data that The Fresh Test is superior to traditional glucose beverages (or equivalent), what are we to do as laboratorians to improve the experience of the pregnant woman who is being screened for GDM?
To this end, we offer the following suggestions based on “expert” opinions. First, glucose beverages should not be swallowed rapidly. The beverages should be ingested slowly (e.g., sipped) over a period of up to 5 minutes . Second, cooling the beverage and/or serving the beverage over ice can improve palatability . Thirdly, provide a calm and comfortable environment for the test. We are hopeful that such simple approaches may somewhat help improve the patient’s experience.
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