Send to

Choose Destination
Am J Obstet Gynecol. 1989 Sep;161(3):638-41.

Do the current standards for glucose tolerance testing in pregnancy represent a valid conversion of O'Sullivan's original criteria?

Author information

Department of Obstetrics and Gynecology, Kaiser Foundation Hospital, Bellflower, CA 90706.


The venous plasma values for the 100 gm glucose tolerance test endorsed by the Second International Workshop-Conference on Gestational Diabetes represent an arbitrary conversion from O'Sullivan's original values. The latter were calculated from whole blood by means of the Somogyi-Nelson method. The factor used to convert the whole blood values to plasma glucose values was empirically derived in a population in whom pregnancy status was not stated. A conversion factor derived from a nonpregnant population may systematically overestimate plasma glucose concentration when applied to a pregnant population. Paired specimens obtained from 995 consecutive pregnant patients were analyzed by the Somogyi-Nelson method on whole blood and the glucose oxidase method on plasma. A conversion formula was derived and was used to estimate plasma glucose values and 95% confidence limits equivalent to whole blood values. Application of this formula yields plasma glucose oxidase glucose tolerance test values of fasting, 96 mg/dl; 1 hour, 172 mg/dl; 2 hours, 152 mg/dl, and 3 hours, 131 mg/dl. These values are all lower than those currently endorsed.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center