The results of the present study showed that gestational diabetes mellitus was associated with significantly higher levels of FPG, HbA1c, and HOMA-IR and lower levels of FINS versus a healthy condition (P < 0.05), which is attributed to the inability of the body function of pregnant women with restricted insulin secretion to compensate for the increased insulin demand, which results in abnormal FPG, HbA1c levels, and HOMA-IR index. This evidence concerns the gene INS and gestational diabetes.