A review is given of the various methods of assessing carbohydrate tolerance in pregnancy. Oral glucose tolerance screening and diagnostic tests have been in use for more than 25 years. They are easily administered, relatively inexpensive, and present reasonable sensitivity; therefore, they continue to be uses quite extensively. However, lack of reproducibility of the results and side effects such as nurses, vomiting, and headache have led to the use of alternate methods including glucose polymer (Polycose) and standard breakfast meals. These methods have been reported to present satisfactory results in clinical practice. Glycosylated hemoglobin (HbA10) and fructosamie assays are also alternate forms of testing carbohydrate metabolism HbA10measurement have been proven insensitive as a screening test for gestatioal diabetes, while their use as an index of overall glucose control remains valuable. The role of fructosamine in the assessment of carbohydrate intolerance remains controversial with conflicting claims made by various investigators regarding its sensitivity in detecting gestational diabetes and its response to alternations in glycemic control. In this review, the relative advantages ad disadvantages of each glucose tolerance test are discussed and recommendations are given regarding their utility in pregnancy.