There was significant heterogeneity among studies (I2 = 98.0%, P < 0.001); however, heterogeneity disappeared or markedly decreased in the subgroups of European populations (I2 = 0.0%, P = 0.531), age ≥ 30 years (I2 = 28.2%, P = 0.223) and WHO diagnostic criteria (I2 = 0.0%, P = 0.490) when stratifying by study location, trimester of chemerin measurement and the diagnostic criteria of GDM. This evidence concerns the gene RARRES2 and gestational diabetes.