Predictive value of the complement factors B and H for women with gestational diabetes mellitus who are at risk of preeclampsia

•The association between serum levels of complement factors B, H and the risk of preeclampsia (PE) in gestational diabetes mellitus (GDM) patients remains unclear.•A total of 503 GDM patients attended GDM education class at Peking University Third Hospital(PUTH) from March 2018 to December 2018. 456 cases were followed until delivery and blood samples were collected during 24–28 gestational weeks to clarify the potential association.•Elevated serum levels of FB in mid-pregnancy may be a potential predictor of predicting the risk of PE in GDM patients. The combination of complement factor B (FB), complement factor H (FH) and triacylglycerol (TG) increased the predictive value.