The number of abnormal plasma glucose values in the oral glucose tolerance test and the feto-maternal outcome of pregnancy

Abstract

Objective: With respect to the feto-maternal outcome of pregnancy both appropriate screening and treatment of gestational diabetes mellitus (GDM) remain a matter of debate. Furthermore, the importance of only one abnormal glucose value at the glucose tolerance test (GTT) is still discussed, including the term “gestational impaired glucose tolerance” with normal fasting but an increased 2 h postprandial glucose value. Study design: We have evaluated the feto-maternal outcome of pregnancy in 152 women with abnormal glucose values during the oral 100 g GTT. The data were analysed with respect to the number of abnormal GTT values and compared to age- and body mass index (BMI)-matched control groups including 304 women with normal GTT values. Results: A positive family history of diabetes was found in 24.4% of the GDM women and in 16.4% of the control group. In 45.9% of the women with abnormal GTT values glucose target levels could be obtained by dietary management, 54.1% required additional insulin therapy. Insulin therapy was administered in 32.8% of the women with one abnormal GTT value, in 65.0% of the women with two abnormal values and in 83.3% of the women with three abnormal values. Compared to the age- and BMI-matched control group the percentage of women with hypertension was increased in women with one, two and three abnormal GTT values. The percentage of LGA and macrosomic infants was significantly increased only in women with three abnormal GTT values. Women with one, two or three abnormal GTT values revealed an increased percentage of caesarean section compared to the control group. Conclusions: Our results show that women with three abnormal GTT values are at an overall increased risk with respect to the feto-maternal outcome of pregnancy. Compared to the control group also women with only one abnormal GTT value revealed an increased risk indicating a need for further control and therapy.