Prophylaxis of Preeclampsia With Low-Dose Aspirin: A Comprehensive Review.

Preeclampsia (PE) is a multifactorial hypertensive disorder of pregnancy and a leading cause of maternal and perinatal morbidity and mortality worldwide. Despite decades of research, its precise pathophysiology remains incompletely understood, though abnormal placentation, endothelial dysfunction, angiogenic imbalance, oxidative stress, and immune dysregulation are recognized contributors. Low-dose aspirin (LDA) has emerged as a safe and effective prophylactic intervention in high-risk pregnancies. It acts primarily by irreversibly inhibiting cyclooxygenase enzymes, restoring the thromboxane A₂/prostacyclin balance, reducing platelet aggregation, and improving uteroplacental perfusion. The daily doses between 60 and 150 mg - most commonly 75 mg - initiated before 16 weeks of gestation significantly reduce the incidence of preterm and early-onset PE, as well as associated complications such as fetal growth restriction (FGR) and preterm delivery. Large clinical trials and meta-analyses have demonstrated that LDA is well tolerated, with minimal risk of maternal or neonatal bleeding. However, challenges persist regarding optimal dose standardization, adherence, and implementation in low-resource settings. Ongoing research emphasizes the need for biomarker-guided screening, personalized dosing, and early risk stratification to enhance prophylactic outcomes. Overall, LDA represents a cost-effective, evidence-based, and globally accessible intervention that substantially reduces the burden of hypertensive disorders in pregnancy and improves maternal-fetal outcomes when administered in an appropriate and timely manner.