When split into GDM and NGT, Gremlin-1 correlated negatively with age (rp = − 0.509, p = 0.008), the Disposition Index (rp = − 0.572, p = 0.007) and the Insulinogenic Index (rp = − 0.599, p = 0.003) in women with NGT at GW < 20, but positively with the Insulinogenic Index (rp = 0.524, p = 0.031) in women with GDM at GW < 20. Here, GREM1 is linked to gestational diabetes.