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

OBJECTIVE: To assess whether aspirin treatment can be discontinued in pregnancies with normal uterine artery pulsatility index (≤90th percentile) at 24-28 weeks. DESIGN: Post-hoc analysis of a clinical trial. SETTING: Nine maternity hospitals in Spain. POPULATION OR SAMPLE: Pregnant individuals at high risk of pre-eclampsia at 11-13 weeks and normal uterine artery Doppler at 24-28 weeks. METHODS: All 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 MEASURES: Incidence of preterm pre-eclampsia. RESULTS: Of 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. CONCLUSIONS: Discontinuing 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.

Clinical effectiveness of routine first-trimester combined screening for pre-eclampsia in Spain with the addition of placental growth factor.

INTRODUCTION: Pre-eclampsia affects 2%-8% of pregnancies and is one of the leading causes of maternal and perinatal morbidity and mortality. First-trimester screening using an algorithm that combines maternal characteristics, mean arterial blood pressure, uterine artery pulsatility index and biomarkers (pregnancy-associated plasma protein-A and placental growth factor) is the method that achieves a greater diagnostic accuracy. It has been shown that daily salicylic acid administration before 16 weeks in women at a high risk for pre-eclampsia can reduce the incidence of preterm pre-eclampsia. However, no previous studies have evaluated the impact of routine first-trimester combined screening for pre-eclampsia with placental growth factor after being implemented in the clinical practice. MATERIAL AND METHODS: This was a multicenter cohort study conducted in eight different maternities across Spain. Participants in the reference group were prospectively recruited between October 2015 and September 2017. Participants in the study group were retrospectively recruited between March 2019 and May 2021. Pre-eclampsia risk was calculated between 11+0 and 13+6 weeks using the Gaussian algorithm combining maternal characteristics, mean arterial pressure, uterine arteries pulsatility index, pregnancy-associated plasma protein-A and placental growth factor. Patients with a risk greater than 1/170 were prescribed daily salicylic acid 150 mg until 36 weeks. Patients in the reference group did not receive salicylic acid during gestation. RESULTS: A significant reduction was observed in preterm pre-eclampsia (OR 0.47; 95% CI: 0.30-0.73), early-onset (<34 weeks) pre-eclampsia (OR 0.35; 95% CI: 0.16-0.77), preterm small for gestational age newborn (OR 0.57; 95% CI: 0.40-0.82), spontaneous preterm birth (OR 0.72; 95% CI: 0.57-0.90), and admission to intensive care unit (OR 0.55; 95% CI: 0.37-0.81). A greater treatment adherence resulted in a significant reduction in adverse outcomes. CONCLUSIONS: Routine first-trimester screening for pre-eclampsia with placental growth factor leads to a reduction in preterm pre-eclampsia and other pregnancy complications. Aspirin treatment compliance has a great impact on the effectiveness of this screening program.

Aspirin Discontinuation at 24 to 28 Weeks' Gestation in Pregnancies at High Risk of Preterm Preeclampsia: A Randomized Clinical Trial.

Importance: Aspirin reduces the incidence of preterm preeclampsia by 62% in pregnant individuals at high risk of preeclampsia. However, aspirin might be associated with an increased risk of peripartum bleeding, which could be mitigated by discontinuing aspirin before term (37 weeks of gestation) and by an accurate selection of individuals at higher risk of preeclampsia in the first trimester of pregnancy. Objective: To determine whether aspirin discontinuation in pregnant individuals with normal soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1:PlGF) ratio between 24 and 28 weeks of gestation was noninferior to aspirin continuation to prevent preterm preeclampsia. Design, Setting, and Participants: Multicenter, open-label, randomized, phase 3, noninferiority trial conducted in 9 maternity hospitals across Spain. Pregnant individuals (n = 968) at high risk of preeclampsia during the first-trimester screening and an sFlt-1:PlGF ratio of 38 or less at 24 to 28 weeks of gestation were recruited between August 20, 2019, and September 15, 2021; of those, 936 were analyzed (intervention: n = 473; control: n = 463). Follow-up was until delivery for all participants. Interventions: Enrolled patients were randomly assigned in a 1:1 ratio to aspirin discontinuation (intervention group) or aspirin continuation until 36 weeks of gestation (control group). Main Outcomes and Measures: Noninferiority was met if the higher 95% CI for the difference in preterm preeclampsia incidences between groups was less than 1.9%. Results: Among the 936 participants, the mean (SD) age was 32.4 (5.8) years; 3.4% were Black and 93% were White. The incidence of preterm preeclampsia was 1.48% (7/473) in the intervention group and 1.73% (8/463) in the control group (absolute difference, -0.25% [95% CI, -1.86% to 1.36%]), indicating noninferiority. Conclusions and Relevance: Aspirin discontinuation at 24 to 28 weeks of gestation was noninferior to aspirin continuation for preventing preterm preeclampsia in pregnant individuals at high risk of preeclampsia and a normal sFlt-1:PlGF ratio. Trial Registration: ClinicalTrials.gov Identifier: NCT03741179 and ClinicalTrialsRegister.eu Identifier: 2018-000811-26.

Maternal and Perinatal Outcomes Associated With Extremely High Values for the sFlt-1 (Soluble fms-Like Tyrosine Kinase 1)/PlGF (Placental Growth Factor) Ratio.

Background There is little knowledge about the significance of extremely high values (>655) for the ratio of sFlt-1 (soluble fms-like tyrosine kinase 1) to PlGF (placental growth factor). We aim to describe the time-to-delivery interval and maternal and perinatal outcomes when such values are demonstrated while assessing suspected or confirmed placental dysfunction based on clinical or sonographic criteria. Methods and Results A multicenter retrospective cohort study was performed on 237 singleton gestations between 20+0 and 37+0 weeks included at the time of first demonstrating a sFlt-1/PlGF ratio >655. Clinicians were aware of this result, but standard protocols were followed for delivery indication. Main outcomes were compared for women with and without preeclampsia at inclusion. In those with preeclampsia (n=185, of whom 77.3% had fetal growth restriction), severe preeclampsia features and fetal growth restriction in stages III or IV were present in 49.2% and 13.5% cases, respectively, at inclusion and in 77.3% and 28.6% cases, respectively, at delivery. In the group without preeclampsia (n=52, 82.7% had fetal growth restriction), these figures were 0% and 30.8%, respectively, at inclusion and 21.2% and 50%, respectively, at delivery. Interestingly, 28% of women without initial preeclampsia developed it later. The median time to delivery was 4 days (interquartile range: 1-6 days) and 7 days (interquartile range: 3-12 days), respectively (P<0.01). Overall, perinatal mortality was 62.1% before 24 weeks; severe morbidity surpassed 50% before 29 weeks but became absent from 34 weeks. Maternal serious morbidity was high at any gestational age. Conclusions An sFlt-1/PlGF ratio >655 is almost invariably associated with preeclampsia or fetal growth restriction that progresses rapidly. In our tertiary care settings, we observed that maternal adverse outcomes were high throughout gestation, whereas perinatal adverse outcomes diminished as pregnancy advanced.