Statistical analysis
All statistical analyzes were performed using IBM SPSS Statistics 21.0 (IBM Corp. Armonk, NY). Numerical variables were expressed as standard deviations and means. The Kolmogorov-Smirnov test was used to interpret the relationship of the data to the normal distribution. The parametric t-test for independent samples and the nonparametric Mann-Whitney U test were used to compare statistical significance between two independent groups in relation to the distribution ranges. Spearman and Pearson correlation tests were performed to evaluate the relationship between the two quantitative variables according to their distribution ratios. Receiver operating characteristic analysis (ROC) was performed to determine the predictive value of EFT for GDM. P values of less than 0.05 were interpreted as statistically significant.