Abstract: Aspirin can improve placental microcirculation and prevent a series of adverse outcomes caused by placental dysfunction. Guidelines recommend generally that the use of low dose aspirin (LDA) in the first trimester can prevent pre-eclampsia, especially preterm pre-eclampsia (less than 37 weeks of delivery), but further studies are needed for its effect on small for gestational age (SGA), abortion and stillbirth. Low molecular weight heparin (LMWH) has a safe anticoagulant effect, but has little or no effect in preventing placental mediated pregnancy complications including pre-eclampsia and SGA. Long-term application of LDA and LMWH during pregnancy did not increase the risk of placental abruption, prenatal and postpartum hemorrhage. This review summarizes the recommended risk factors for pre-eclampsia and early screening models, discusses the theoretical basis for the use of LDA and LMWH as well as the research progress in the prevention of complications. Ultimately, we hope it will help the obstetricians gain a deeper understanding of the use of LDA and LMWH in clinical practice.

Key words: Pre-eclampsia;, Aspirin;, Heparin, low-molecular-weight, Infant, small for gestational age, Pregnancy outcome