A simple score to predict fetal outcomes in gestational diabetes mellitus

Strict glycemic control is critical in preventing adverse maternal and fetal outcomes with gestational diabetes mellitus (GDM), but frequently results in recurrent maternal hypoglycemia and is often impracticable. This study was done to determine whether a more lenient strategy might provide satisfactory outcomes and to formulate a glycemic score for prognostication of fetal outcomes.

A prospective non-interventional study was conducted on consecutive patients admitted with GDM between May 2007 and August 2009. Patients with pre-gestational diabetes were excluded. All patients received treatment at the discretion of treating consultants. Glycemic control was estimated by recording mean values of all glucose profiles performed. Fasting and postprandial blood glucose levels below 95 mg/dl and 120 mg/dl, respectively, were considered controlled. A glycemic score was calculated based on the number of mean blood glucose values controlled. Fetal outcomes were noted.

Ninety-four patients with GDM were included. The glycemic score was significantly predictive of adverse fetal outcomes (p < 0.001). Analysis by receiver operating characteristic (ROC) curve showed good sensitivity and specificity for macrosomia (78.3% and 81.8%, respectively) and congenital anomalies (73.9% and 66.7%, respectively) with a glycemic score of 2 or less [area under curve (AUC) 0.768; odds ratio (OR), 11.17; 95% Confidence Interval (CI), 2.58-48.35; p < 0.001; and AUC 0.765; OR, 2.22; 95% CI, 0.71-6.92; p = 0.055, respectively]. Binomial logistic regression confirmed the glycemic score to be independently predictive of fetal outcome (p = 0.015).

The glycemic score is a sensitive and specific prognostic marker. Tight control of three of four values of blood glucose within the glucose profile appears sufficient to prevent adverse fetal outcomes.