Factors predicting the need for insulin therapy in patients with gestational diabetes mellitus

To determine the possible factors predicting the insulin requirement in pregnancies complicated by gestational diabetes mellitus (GDM).

A total of 294 patients with GDM diagnosed by the 100-g/3-h oral glucose tolerance test (OGTT) were studied. The following factors were analyzed: maternal age, nulliparity, family history of diabetes, prepregnancy BMI, prior GDM, prior fetal macrosomia, multiple pregnancy, polyhydramnios, gestational age at diagnosis of GDM, smoking, hypertension, number of abnormal 100-g/3-h OGTT values, and glycated hemoglobin (HbA1c). The association between each factor and the need for insulin therapy was then analyzed individually. The performance of these factors to predict the probability of insulin therapy was estimated using a logistic regression model.

Univariate analysis showed a positive correlation between insulin therapy and prepregnancy BMI, family history of diabetes, hypertension, prior GDM, prior fetal macrosomia, number of abnormal 100-g/3-h OGTT values, and HbA1c (P<0.05). Prepregnancy BMI, family history of diabetes, number of abnormal 100-g/3-h OGTT values and HbA1c were statistically significant variables in the logistic regression model.

The probability of insulin therapy can be estimated in pregnant women with GDM based on prepregnancy BMI, family history of diabetes, number of abnormal 100-g/3-h OGTT values, and HbA1c concentration.