To find the correlation among AFM, SERPINB1, and NRG4 serum levels in GDM, the Pearson analysis was then performed, and the result revealed a significant correlation between AFM and SERPINB1 (r = 0.776, P < 0.001), AFM and NRG4 (r = −0.799, P < 0.001), as well as SERPINB1 and NRG4 (r = −0.783, P < 0.001) in serum of GDM patients (Figure 3). Here, NRG4 is linked to gestational diabetes.