Isolated abnormal value on the 3-hour glucose tolerance test: which of them is related with macrosomia?

Aim 

The clinical significance of an isolated abnormal value on the 3 h–100 g oral glucose tolerance test (OGTT) remains unclear. The aim of this study is to evaluate retrospectively the obstetric outcome of patients with isolated one abnormal OGTT value according to the 1, 2, and 3 hours values.

Metarials and methods 

From January 2003 through June 2009, all consecutive pregnant women were screened for gestational diabetes. The OGTT results were interpreted according to the criteria of Carpenter and Coustan. Women with one abnormal value were grouped according to corresponding time of increased levels (Group 1: Serum glucose concentration > 180 mg/dL at hour 1, Group 2: Serum glucose concentration > 155 mg/dL at hour 2, and
Group 3: Serum glucose concentration > 140 mg/dL at hour 3). Three groups were compared for classical risk factors, fasting glucose levels in the first trimester, incidence of large for gestational age (LGA) baby and macrosomia, birth weight and birth week.

Bulgular

There were 4930 women, who had undergone GDM screening with 50 g OGTT. Of these, 1275 women screened positive and subsequently underwent further diagnostic testing for GDM by 100 g-OGTT. 279 women had gestational diabetes (5.6 %), whereas 175 women had single abnormal value (3.5 %). Three groups were similar concerning age, parity, and gestational age in the first trimester. The incidence of family history was significantly higher in Group 1 (46.2 % for Group 1 and 23.7% for Group 2, p=0.007). There were no significant differences among groups regarding the mean fasting blood glucose level at the first trimester, birth weight and birth week. The mean glucose levels were significantly higher at the time of 50 g OGTT in Group 1 (161.25 ±15.73 for Group 1 and 152.20± 12.94 for Group 2, p=0.011). The incidence of LGA (3.8 % for Group 1, 20.3 % for Group 2, 13.2 % for Group 3, p=0.008) and macrosomia (5.1 % for Group 1, 18.6 % for Group 2, 15.8 % for Group 3, p=0.039) was significantly higher in Group 2 .

Sonuç

Our results show that the implications of a single elevated glucose tolerance test value vary in relation to the timing of the abnormal value. Moreover, even relatively mild degrees of glucose intolerance at hour 2 might be associated with larger babies.

Anahtar Kelimeler

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