C9 and gestational diabetes: We found that 11 CBs were significantly upregulated in women with GDM compared to controls, i.e., APOA5, APOE, F9, F10, F12, C1S, FGA, IGF binding protein 5 (IGFBP-5), PRG4, SAP and PON1 and 13 CBs were found to be significantly downregulated in women with GDM compared to controls, i.e., were C4BPA, F5, C6, C7, C8B, C8G, C9, CFH, EPN, GSN, IGHM, P and SPP24; the remaining CBs were not significant in women with GDM compared to controls.