Objective To investigate the efficacy of low-dose aspirin in combination with low-molecular-weight heparin calcium for the prevention of preeclampsia,as well as its impact on hemorheological status and maternal-infant outcomes.Methods A retro-spective review was conducted on data from 367 pregnant women identified with risk factors for preeclampsia,who were examined in the Obstetrics Department of the First Affiliated Hospital of Hebei North University from June 2018 to December 2021.Participants were cate-gorized into three groups based on the preventive medication regimen they received:Group A(low-dose aspirin,n=137),Group B(low-molecular-weight heparin calcium,n=107),and Group C(combination of low-dose aspirin and low-molecular-weight hep-arin calcium,n=123).The study compared coagulation function parameters[prothrombin time(PT),activated partial thromboplastin time(APTT),D-dimer(DD)and fibrinogen(FIB)],hemorheological measures(whole blood viscosity,plasma viscosity,hemato-crit),and adverse drug reactions before and after the administration of medication.Follow-up continued until delivery to document pla-cental indicators[vascular endothelial growth factor(VEGF),microvessel density(MVD)],and maternal-infant outcomes.Results After treatment,the DD,FIB,whole blood viscosity,plasma viscosity,hematocrit and the incidence rate of premature birth in group C were lower than those in groups A and group B while the positive expression rate of VEGF,MVD,PT,APTT and Apgar score were higher than those in group A and group B(all P＜0.05).There were no statistical differences in the coagulation function,hemorheology and placental indicators between group A and group B as well as the incidence rates of eclampsia,cesarean section,postpartum hemorrhage and stillbirth and incidence rates of adverse drug reactions among the three groups(all P＞0.05).Conclusion Both low-dose aspirin and low-molecular-weight hep-arin calcium can play a preventive role in preeclampsia,and can improve the coagulation function,hemorheology and placental indicators.The combination of the two drugs has a better preventive effect and does not significantly increase the risk of medication.