Preeclampsia is a major cause of maternal and perinatal morbidity and mortality worldwide. Low-dose aspirin started in the first trimester reduces the risk of preeclampsia in high-risk women. Low molecular weight heparin (LMWH) has shown potential benefits in addition to aspirin for preventing preeclampsia through its anticoagulant, anti-inflammatory, and endothelial protective effects. However, current evidence is limited and conflicting regarding the added value of LMWH to aspirin. This randomized controlled trial aims to evaluate the efficacy of combined aspirin and LMWH, compared to aspirin alone, for reducing the incidence of preeclampsia in high-risk gravidas.
Singleton pregnancy
High risk for preeclampsia (risk >1:150) based on FMF screening algorithm combining first-trimester ultrasound, biochemical markers, and medical history
Gestational age <16 weeks at enrollment
Maternal age ≥18 years
Multiple pregnancy
Current permanent aspirin use for other medical indications
Serious congenital fetal abnormality detected on ultrasound
Contraindication to aspirin or low molecular weight heparin including: known hypersensitivity, active peptic ulcer disease, bleeding disorders or coagulopathy, severe thrombocytopenia (platelet count <100,000/μL), active or recent significant bleeding, history of heparin-induced thrombocytopenia