Mid‐trimester uterine artery Doppler for aspirin discontinuation in pregnancies at high risk for preterm pre‐eclampsia: Post‐hoc analysis of StopPRE trial

Abstract

ObjectiveTo assess whether aspirin treatment can be discontinued in pregnancies with normal uterine artery pulsatility index (≤90th percentile) at 24–28 weeks.DesignPost‐hoc analysis of a clinical trial.SettingNine maternity hospitals in Spain.Population or SamplePregnant individuals at high risk of pre‐eclampsia at 11–13 weeks and normal uterine artery Doppler at 24–28 weeks.MethodsAll participants received treatment with daily aspirin at a dose of 150 mg. Participants were randomly assigned, in a 1:1 ratio, either to continue aspirin treatment until 36 weeks (control group) or to discontinue aspirin treatment (intervention group), between September 2019 and September 2021. In this secondary analysis, women with a UtAPI >90th percentile at 24–28 weeks were excluded. The non‐inferiority margin was set at a difference of 1.9% for the incidence of preterm pre‐eclampsia.Main outcome measuresIncidence of preterm pre‐eclampsia.ResultsOf the 1611 eligible women, 139 were excluded for UtAPI >90th percentile or if UtAPI was not available. Finally, 804 were included in this post‐hoc analysis. Preterm pre‐eclampsia occurred in three of 409 (0.7%) women in the aspirin discontinuation group and five of 395 (1.3%) women in the continuation group (−0.53; 95% CI −1.91 to 0.85), indicating non‐inferiority of aspirin discontinuation.ConclusionsDiscontinuing aspirin treatment at 24–28 weeks in women with a UtAPI ≤90th percentile was non‐inferior to continuing aspirin treatment until 36 weeks for preventing preterm pre‐eclampsia.

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“…Recent studies have suggested that it may be possible to stop aspirin at 28 weeks’ gestation if the angiogenic ratio (sFlt-1:PlGF) and/or the UtAPI are normal [ 254 , 255 ]. Mendoza et al performed a multicenter, open-label, randomized trial of 936 pregnant women who were identified as being at high risk of preterm PE during first-trimester screening (StopPRE trial) [ 254 ].…”

“…Bonacina et al performed a post hoc analysis of the StopPRE trial described above [ 255 ]. In this secondary analysis, women with a UtAPI greater than the 90th percentile were excluded.…”

“…Discontinuation of the aspirin at 24–28 weeks’ gestation in women with a UtAPI index lower than the 90th percentile was non-inferior to continuing the aspirin treatment until 36 weeks for preventing preterm PE. Women in the intervention group had significantly less minor bleeding complications than women in the control group [ 255 ]. These findings are consistent with previous cohort studies showing that low-dose aspirin use during pregnancy may be associated with increased postpartum bleeding and hematoma [ 256 ].…”

“…The authors of this secondary analysis of the StopPRE trial concluded that high-risk women commenced on aspirin at <16 weeks’ gestation who had either an sFlt-1:PlGF ratio < 38 or a UtAPI lower than the 90th percentile could discontinue aspirin at 24–28 weeks [ 255 ]. If further large trials confirm these findings, ceasing aspirin at 24–28 weeks could result in increased compliance and reduced bleeding risk, without the loss of treatment efficacy.…”

Aspirin for those at high risk: When to stop?

“…Dear Dr. Papageorghiou, Bonacina et al report the results of a post-hoc analysis of the StopPRE trial. 1,2 In the trial, women identified by screening at 11-13 weeks of gestation as being at high risk for preterm pre-eclampsia (PE) were treated with aspirin (150 mg/day).…”