{Reference Type}: Journal Article
{Title}: Aspirin 162 mg versus 81 mg for Preeclampsia Prophylaxis in High-risk Obese Individuals: A Comparative Effectiveness Open Label Randomized Trial (ASPREO).
{Author}: Amro FH;Blackwell SC;Pedroza C;Backley S;Bitar G;Daye N;Bartal MF;Chauhan SP;Sibai BM;
{Journal}: Am J Obstet Gynecol
{Volume}: 0
{Issue}: 0
{Year}: 2024 Jul 6
{Factor}: 10.693
{DOI}: 10.1016/j.ajog.2024.06.038
{Abstract}: <B>BACKGROUND: </B>In the United States, leading medical societies recommend 81 mg of aspirin daily for the prevention of preeclampsia (PE) in women at risk, whereas the NICE guidelines in the UK recommend a dose as high as 150 mg of aspirin. Recent data also suggest that in the obese population, inadequate dosing or aspirin resistance may impact the efficacy of aspirin at the currently recommend doses.<BR><B>OBJECTIVE: </B>We evaluated whether daily administration of 162 mg aspirin would be more effective compared to 81 mg in decreasing the rate of PE with severe features in high-risk obese pregnant individuals.<BR><B>METHODS: </B>We performed a randomized trial between May 2019 and November 2022. Individuals at 12 to 20-weeks gestational age (GA) with a BMI ≥ 30 kg/m2 at time to enrollment, and at least one of three high risk factors: history of PE in a prior pregnancy, at least stage I hypertension documented in the index pregnancy, pre-gestational diabetes or gestational diabetes diagnosed prior to 20 weeks GA were randomized to either 162 mg or 81 mg of aspirin daily till delivery, participants were not blinded to treatment allocation. Exclusion criteria were: multifetal gestation, known major fetal anomalies, seizure disorder, baseline proteinuria, on aspirin due to other indications, or contraindication to aspirin. The primary outcome was PE with severe features (PE or superimposed PE with severe features, eclampsia, or HELLP). Secondary outcomes included rates of preterm birth due to PE, small for gestational age (SGA), postpartum hemorrhage, abruption, and medication side effects. A sample size of 220 was needed using a preplanned Bayesian analysis of the primary outcome to estimate the posterior probability of benefit or harm with a neutral informative prior.<BR><B>RESULTS: </B>Of 343 eligible individuals, 220 (64.1%) were randomized. The primary outcome was available for 209/220 (95%). Baseline characteristics were similar between groups, median gestational age at enrollment was 15.9 weeks in the 162 mg aspirin group and 15.6 weeks in the 81 mg aspirin group. Enrollment prior to 16 weeks occurred in 55/110 of those assigned to 162 mg and 58/110 of those assigned to 81 mg of aspirin. The primary outcome occurred in 35% in the 162 mg aspirin group and in 40% in the 81 mg aspirin group (posterior relative risk, 0.88; 95% credible interval, 0.64-1.22). Bayesian analysis indicated a 78% probability of a reduction in the primary outcome with 162 mg aspirin compared to 81 mg aspirin dose. Rates of indicated preterm birth due to preeclampsia (21% vs 21%), SGA (6.5% vs 2.9%), abruption (2.8% vs 3.0%) and postpartum hemorrhage (10% vs 8.8%) were similar between groups. Medication adverse effects were also similar.<BR><B>CONCLUSIONS: </B>Among high-risk obese individuals, there was 78% probability of benefit that 162 mg aspirin compared to 81 mg will decrease the rate of PE with severe features. With a best estimate of a 12% reduction when using 162 mg of aspirin in comparison to 81 mg of aspirin in this population. This trial supports doing a larger multicenter trial.