Objective To investigate the relationship between the expression of microRNA-15a (miR-15a) and fetal heart malformation in patients with gestational diabetes mellitus (GDM).

Methods A total of 891 patients with GDM were selected as disease group and 891 healthy pregnant women were selected as healthy group, the expression of serum miR-15a was detected and compared between the two groups. The disease group was divided into malformed group and non-malformed group according to whether fetal heart malformation occurred, serum miR-15a expression and general data of the two groups were compared. The patients in the disease group were divided into group A and group B according to the confirmed gestational age, and the patients with poor blood glucose control were divided into group C and group D according to the degree of fasting blood glucose elevation. Multivariate Logistic regression analysis was used to analyze the influencing factors of fetal heart malformation in GDM patients. Receiver operating characteristic (ROC) curve was drawn to analyze the predictive value of serum miR-15a expression in fetal heart malformation in GDM patients.

Results Serum miR-15a expression in the disease group was significantly higher than that in the healthy group (P < 0.001). The incidence of fetal heart malformation in GDM patients was 2.87% (24/835). The proportion of serum miR-15a expression, age, pre-pregnancy body mass index, adverse pregnancy history and poor blood glucose control in the malformed group was significantly higher than that in the non-malformed group, and the proportion of regular folic acid administration in early pregnancy was significantly lower than that in the non-malformed group (P < 0.05). There was no significant difference in serum miR-15a expression and incidence of fetal heart malformation between the group A and group B (P>0.05). The expression of serum miR-15a and the incidence of fetal heart malformation in the group D were significantly higher than those in the group C (P < 0.05). Serum miR-15a expression (OR=16.651, 95%CI, 6.252 to 44.344), age (OR=1.078, 95%CI, 1.006 to 1.156), poor blood glucose control (OR=3.404, 95%CI, 1.852 to 5.137) were the influencing factors of fetal heart malformation in GDM patients (P < 0.05). The optimal critical value, sensitivity, specificity and area under the curve for predicting fetal heart malformation in GDM patients were 2.34, 87.50%, 73.24% and 0.827 (95%CI, 0.799 to 0.852), respectively.

Conclusion In GDM patients, serum miR-15a expression is abnormally elevated, which is an effective indicator for predicting fetal heart malformation in GDM patients.