Strawberry Candy Twists as an Alternative Screen for Gestational Diabetes: A Prospective Trial

The aim now is to perform a large, prospective trial to test Twizzlers® as a cost effective glucola alternative in a gravid population to determine its sensitivity, specificity, PPV (positive predictive value) and NPV (negative predictive value) alongside ROC (receiver operating curve) from a population-based cohort.

Participants will be enrolled among the pregnant patients in the Harris Health System Obstetrics Clinics who are either due for the standard glucola GCT (glucose challenge test) or who have had their glucola screening but have not had the 3 hour GTT (glucose tolerance test). These women will be offered the opportunity to consume the Twizzler equivalent of the 50 gm glucola beverage (10 strawberry flavored Twizzlers) and to have their venous blood glucose checked 1 hour post consumption. This will all be done while the patient is in clinic and will not necessitate any extra clinic visits on their behalf. They will then go on to be scheduled for their confirmatory 3 hour glucose tolerance tests if indicated by any abnormality in either their glucola GCT or their Twizzlers challenge. The efficacy of Twizzlers will then be compared to the 50 gm glucola beverage as a screen for gestational diabetes. Specifically, the sensitivity, specificity, PPV, NPV, NNT (number needed to treat), ROC, and referral rates for each mode of screening will be calculated.

For the Twizzler portion of the study, the subjects will consume 10 strawberry Twizzlers within 5 minutes. One hour after consumption begins each participant will have a blood draw to check a serum glucose level. Within the same day, the samples will be delivered to Dr. Morey Haymond's lab for analysis.

Serum glucose and insulin levels will be tested on each sample. The amount of each blood sample will be approximately 10 ml of blood (2 teaspoons). Sample collection (blood draws; venipuncture) will allow for testing the serum glucose levels of subjects after consumption of Twizzlers. These values will be used for analysis to determine if Twizzlers are truly equivalent to the Glucola beverage. Ultimately, the patient's will only undergo 1 extra venipuncture than what they would have had as part of their routine prenatal care if both screening tests are normal. There is a possibility of undergoing a 3 hour GTT that would not have otherwise been performed if the subjects Twizzlers screen is elevated but glucola was normal.

Participants will receive a phone call to report any abnormal values on their GCT as per standard clinical operating measures, and will have their GTT scheduled with the nursing staff. Based on prior studies, a notable rate of false-positives is not anticipated with the Twizzler GCT. In the rare occasion that such occurs (i.e., screen positive by Twizzler but not by glucola beverage) they will be informed of the need for a 3 hour GTT. This will be covered by the study costs, and their insurance will not be charged.