The OR of CD19 on PB/PC on GDM risk was estimated to be 0.902 (95% CI: 0.839–0.970, P = 0.005, PFDR = 0.038) by the IVW method, whereas the MR Egger (95% CI: 0.770–1.009, OR = 0.881, P = 0.083) and weighted median (95% CI: 0.820–1.013, OR = 0.911, P = 0.085) analyses were consistent with the IVW. Here, CD19 is linked to gestational diabetes.