Comparing the Efficacy of 75mg Versus 150mg Aspirin for the Prevention of Preeclampsia in High-Risk Pregnant Women

Not yet recruiting

• Conditions: Preeclampsia (PE)
• Interventions: Drug: Aspirin Tablets

• Registration Number: NCT07041385
• Lead Sponsor: Shalamar Hospital

Brief Summary

This study aims to evaluate the effectiveness of 75 mg aspirin versus 150 mg aspirin in preventing preeclampsia among individuals with high risk for the condition. Existing literature suggests that the 150 mg aspirin dose may exhibit superior efficacy, yet inconclusive evidence exists in our local setting.

Detailed Description

Pre-eclampsia defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg on at least two occasions 4 h apart developing after 20 weeks of gestation in previously normotensive women. Hypertension was defined as proteinuria ≥ 300 mg in 24 h or two readings of at least ++ on dipstick analysis of midstream or catheter urine specimens if no 24-h collection was available. Pre-eclampsia superimposed on chronic hypertension was defined as significant proteinuria (as defined above) developing after 20 weeks of gestation in women with known chronic hypertension (history of hypertension before conception or presence of hypertension at booking visit before 20 weeks' gestation in the absence of trophoblastic disease). Pre-eclampsia is a major factor in both maternal and fetal morbidity and mortality. The most widely investigated preeclampsia prevention medication is low dose Aspirin. However, guidelines differ considerably regarding the prophylactic dose of Aspirin for preeclampsia. Pre-eclampsia (PE) affects 5-7% of all pregnancies and along with eclampsia is the major contributor to maternal morbidity and 10-15% of maternal mortality and also perinatal mortality. Pre-eclampsia (PE) accounts for a notable portion of maternal morbidity and mortality, with varied prevalence across regions within countries. PE not only affects maternal health during pregnancy but also predisposes women to long-term cardiovascular complications, emphasizing the need for early screening and preventive measures. Evidence-based guidelines recommend aspirin for high-risk women, usually 75 mg from 12 weeks' gestation and if possible before 20 weeks. Low dose aspirin administration can reduce vasoconstriction and decreases thrombosis of the vessels related to placenta, thereby increases blood flow and protects against to pregnancy related complication like preeclampsia, IUGR or FGR. One of the major therapeutic interventions to prevent preeclampsia is the use of Aspirin (a COX-II inhibitor with anti-inflammatory and anti-thrombotic properties). Initiating low-dose aspirin (LDA) therapy in early pregnancy from 12 weeks can prevent the onset of pre-eclampsia or delay it. The antiplatelet and vasodilatory effect of aspirin induced by the inhibition of cyclooxygenase-1 (COX-1) and reduced production of thromboxane, a potent vasoconstrictor and platelet aggregator, enhances placental blood circulation. Moreover, potential anti-inflammatory properties can improve endothelial dysfunction and oxidative stress, which are the central pieces of preeclampsia mechanisms.

A randomized control study was conducted at the Department of Obstetrics and Gynaecology of Ziauddin University Hospital Kemari, Karachi concluded that the effectiveness of Aspirin 75mg was 53% compared to 70% of Aspirin 150mg in the prevention of pre-eclampsia among high-risk women starting at 11-14 weeks. Another study was conducted in Department of Obstetrics and Gynecology, Services Hospital, Lahore concluded that in the 75 mg group, the efficacy was achieved in 94 (78.3%) patients, whereas in the 150 mg group, the efficacy was achieved in 108 (90.0%) patients. This difference was statistically significant. i.e., p-value=0.013.

The dose of aspirin used in most hospital settings is low dose, which has its benefits outweigh the risks and side effects of the drug. Many studies evaluated low doses of Aspirin 60-80mg showing a 10%-50% reduction in the incidence of preeclampsia, while a few studies also evaluated the efficacy of a 150mg dos. Keeping abreast of the variability of responses to different doses of the same medicine; this study compared low dose Aspirin (75mg) with higher dose (150mg). To our knowledge, this is among very few studies to investigate the effectiveness of relatively higher doses of aspirin in the Pakistani population.

Study Timeline

• Status Verified: 2025-06
• Study First Submitted: 2025-06-19
• Study First Submitted QC: 2025-06-19
• Last Update Submitted: 2025-06-19
• Study First Posted: 2025-06-27
• Last Update Posted: 2025-06-27
• Study Start: 2025-07-01
• Primary Completion: 2026-06-30
• Study Completion: 2026-07-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 340

Inclusion Criteria

1. Screen positive women
2. Age 18 - 30 y
3. Gestational Age 11 - 13+6 weeks
4. Singleton Pregnancy
5. Estimated risk for preterm PE of > 1 in 100 (Reference - Fetal Medicine Foundation)

Exclusion Criteria

1. Screen negative women
2. Age > 30 y
3. Gestational Age > 14 weeks
4. Multiple Gestation
5. Estimated risk for preterm PE of < 1 in 100 (Reference - Fetal Medicine Foundation)

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Pregnant Females	Aspirin Tablets	All pregnant patients who are attending Out patient department OBGYN from 11 to 13+6 weeks of gestation, having singleton pregnancy without any co-morbidities.

Primary Outcome Measures

Name	Time	Method
Pre - eclampsia	9 months	PE (Pre-eclampsia) Yes / No Early Onset - Pre-eclampsia (\<34 weeks) Yes / No Late Onset - Pre-eclampsia (\>34 weeks) Yes / No

Secondary Outcome Measures

Name	Time	Method
Delivery	9 months	Preterm - Pre-eclampsia Delivery (\<37 weeks) Yes / No Term Delivery - Pre-eclampsia (\>37 weeks) Yes / No

Trial Locations

Locations (1)

Shalamar Hospital; 🇵🇰 Lahore, Punjab, Pakistan