Does a high carbohydrate preparatory diet affect the 3-hour oral glucose tolerance test in pregnancy?
The aim of this study was to determine the effect of a high carbohydrate preparatory diet on the performance of the 3-hour oral glucose tolerance test (GTT) in pregnancy. This prospective clinical trial was performed at a university hospital outpatient obstetric clinic. Gravidas who had an abnormal blood sugar screening test were asked to ingest one of two preparatory diets: > or = 150g/day of carbohydrate for 3 days (Carbo) or six Snickers candy bars per day for 3 days (Candy), or to remain on their usual diet (Ad lib) prior to the GTT. A 100g oral GTT was performed after an overnight fast, and blood glucose values were determined at 1, 2, and 3 hours. Patients with either a fasting whole blood glucose > 120 mg/dl or > or = two abnormal values on the GTT were considered to have gestational diabetes mellitus and received diet therapy. Women who failed diet therapy also received insulin. Our primary outcome parameter was the intergroup incidence of gestational diabetes mellitus. Other p
