Effectiveness Of Aspirin In The Prevention Of Preeclampsia In High Gestosis Scored Women Attending Tertiary Level Hospital In Kathmandu: A Randomized Controlled Trial

Preeclampsia is a leading cause of maternal and perinatal morbidity and mortality worldwide, particularly in low- and middle-income countries. It is a multisystem disorder of pregnancy characterized by new-onset hypertension after 20 weeks of gestation, often accompanied by proteinuria or evidence of end-organ dysfunction. The pathophysiology of preeclampsia involves abnormal placentation, endothelial dysfunction, increased platelet activation, and an imbalance between vasoconstrictive and vasodilatory prostaglandins.

Low-dose Aspirin (acetylsalicylic acid) has been shown to reduce the risk of preeclampsia through irreversible inhibition of cyclooxygenase-1 (COX-1), resulting in reduced thromboxane A2 production, decreased platelet aggregation, and improved uteroplacental perfusion. International guidelines recommend prophylactic low-dose Aspirin for pregnant women at high risk of preeclampsia; however, there is ongoing debate regarding the optimal dose. Both 75 mg and 150 mg doses are currently used in clinical practice, but comparative evidence in South Asian populations, including Nepal, remains limited.

This investigator-initiated, non-commercial randomized controlled trial is designed to compare the effectiveness and safety of Aspirin 75 mg versus Aspirin 150 mg once daily for the prevention of preeclampsia in pregnant women identified as high risk based on a high gestosis score. The study is conducted at a tertiary-level teaching hospital in Kathmandu, Nepal.

Participants will be enrolled during early pregnancy and randomized in a 1:1 allocation ratio to receive either Aspirin 75 mg or Aspirin 150 mg orally once daily. Randomization will be generated using a computer-based random sequence with block randomization to ensure balance between treatment groups. Allocation concealment will be achieved using sequentially numbered, opaque, sealed envelopes prepared by an independent individual not involved in participant recruitment or outcome assessment.

Due to the difference in tablet strength, the trial is open-label. To minimize bias, all participants will receive identical standard antenatal care according to institutional and national guidelines, and outcome assessment will follow predefined diagnostic criteria. Data analysis will be conducted by investigators blinded to treatment allocation.