(640) Do women with one abnormal value of oral-glucose-tolerance-test according to Carpenter and Coustan have gestational-diabetes-mellitus?

Gestational diabetes mellitus (GDM) is diagnosed by the two step strategy of performing 50g glucose challenge test (GCT) followed by 100g oral glucose tolerance test (OGTT). The accepted cutoffs for GDM diagnosis using the 100g OGTT are two elevated values according to the criteria of either Carpenter and Coustan (C&C) or the 1979 National Diabetes Data Group. In the present study we examined the effect of one OGTT abnormal value only according to C&C criteria on pregnancy outcomes.

Study Design:

A population based retrospective cohort study of women who delivered at Emek medical center in Israel between July 2013 and September 2021 was conducted. Women were divided to the following groups: (1) Women without GDM (either normal GCT or OGTT; N=14,450), (2) women with one abnormal OGTT value only according to C&C (fasting glucose 95-104, one hour 180-189, 2 hours 155-164 and 3 hours 140-144 mg/dL; N=661), and (3) women with GDM defined as at least two abnormal OGTT values according to C&C (N=904). Only the last group was treated for GDM. The primary outcome was the rate of large for gestational age (LGA) neonates.

Results:

Univariable and multivariable analyses are presented in the table. After controlling for background characteristics, one abnormal glucose value increased the risk, compared to the control group, for LGA (OR_adj1.9 95%CI[1.6-2.4]), macrosomia (2.4 [1.9-3.2]), hypertensive diseases of pregnancy (1.4 [1.07-1.9]) and shoulder dystocia (3 [1.2-7.8]). The risk for LGA and macrosomia was also higher in the one abnormal glucose value group compared to the two abnormal glucose values group (1.4 [1.1-1.9] and 2.1 [1.4-3.1], respectively).

Conclusion:

Women with one abnormal OGTT value, according to the C&C only, had worse outcome than normo-glycemic women or women with GDM. Those women should be considered as having GDM.