High Risk For Preterm Preeclampsia Research Articles

Placental growth factor at 24-28 weeks for aspirin discontinuation in pregnancies at high risk for preterm preeclampsia: Post hoc analysis of StopPRE trial.

This study aims to evaluate the safety of discontinuing aspirin treatment at 24-28 weeks in women at high risk after first-trimester combined screening for preeclampsia (PE) and normal placental growth factor (PlGF) levels at 24-28 weeks of gestation. This is a post hoc analysis of the StopPRE trial, conducted at nine Spanish maternity hospitals from September 2019 to September 2021. In the StopPRE trial, all high-risk single pregnancies identified during first-trimester screening for PE were treated with 150 mg of daily aspirin. Out of 1604 eligible women with a soluble fms-like tyrosine kinase-1 to PlGF ratio (sFlt-1/PlGF) ≤38 at 24-28 weeks, 968 were randomly assigned in a 1:1 ratio to either continue aspirin until 36 weeks (control group) or discontinue it (intervention group). In this secondary analysis, only women with PlGF ≥100 pg/mL at 24-28 weeks were included. As in the StopPRE trial, the non-inferiority margin was set at a 1.9% difference in preterm PE incidence between the groups. Among the 13 983 screened pregnant women, 1984 (14.2%) were deemed high-risk for preterm PE, of which 397 (20.0%) were ineligible, 636 declined participation, and 32 were excluded. Ultimately, 919 women with PlGF >100 pg/mL were randomized and included in this analysis. Preterm PE occurred in 0.9% of the intervention group (4 out of 465) and 1.5% of the control group (7 out of 454), indicating non-inferiority of aspirin discontinuation. There were no significant differences between the groups in adverse pregnancy outcomes before 37 weeks, at <34 weeks, or ≥37 weeks. Minor antepartum hemorrhage incidence was significantly lower in the intervention group (absolute difference, -5.96; 95% CI, -10.10 to -1.82). Discontinuation of aspirin treatment at 24-28 weeks in women with PlGF levels ≥100 pg/mL was non-inferior to continuing until 36 weeks for preventing preterm PE. However, these findings should be interpreted with caution, as they originate from a subanalysis of the StopPRE trial.

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

To assess whether aspirin treatment can be discontinued in pregnancies with normal uterine artery pulsatility index (≤90th percentile) at 24-28 weeks. Post-hoc analysis of a clinical trial. Nine maternity hospitals in Spain. Pregnant individuals at high risk of pre-eclampsia at 11-13 weeks and normal uterine artery Doppler at 24-28 weeks. 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. Incidence of preterm pre-eclampsia. 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. 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.

Evaluation of first trimester maternal serum inhibin-A for preeclampsia screening.

International professional organizations recommend aspirin prophylaxis to women screened high risk for preterm preeclampsia (PE) in the first trimester. The UK Fetal Medicine Foundation (FMF) screening test for preterm PE using mean arterial pressure (MAP), uterine artery pulsatility index (UTPI) and placental growth factor (PlGF) was demonstrated to have lower detection rate (DR) in Asian population studies. Additional biomarkers are therefore needed in Asian women to improve screening DRs as a significant proportion of women with preterm and term PE are currently not identified. To evaluate maternal serum inhibin-A at 11-13 weeks as an alternative to PlGF or as an additional biomarker within the FMF screening test for preterm PE. This is a nested case-control study using pregnancies initially screened at 11-13 weeks for preterm PE using the FMF triple test in a non-intervention study conducted between December 2016 and June 2018. Inhibin-A levels were retrospectively measured in 1,792 singleton pregnancies, 112 (1.7%) with PE matched for time of initial screening with 1,680 unaffected pregnancies. Inhibin-A levels were transformed to multiple of the expected median (MoM). The distribution of log10 inhibin-A MoM in PE and unaffected pregnancies and the association between log10 inhibin-A MoM and gestational age (GA) at delivery in PE were assessed. The screening performance determined by area under receiver operating characteristic curves (AUC) and detection rates (DRs) at a 10% fixed false positive rate (FPR), for preterm and term PE was determined. All risks for preterm and term PE were based on the FMF competing risk model and Bayes theorem. Differences in AUC (ΔAUC) between different biomarker combinations were compared using the Delong test. McNemar's test was used to assess the off-diagonal change in screening performance at a fixed 10% FPR after adding inhibin-A or replacing PlGF in the preterm PE adjusted risk estimation model. Inhibin-A levels in unaffected pregnancies were significantly dependent on GA, maternal age and weight and were lower in parous women with no previous history of PE. Mean log10 inhibin-A MoM in any-onset PE (p<0.001), preterm (p<0.001) and term PE (p = 0.015) pregnancies were all significantly higher than that of unaffected pregnancies. Log10 inhibin-A MoM was inversely but not significantly correlated (p = 0.165) with GA at delivery in PE pregnancies. Replacing PlGF with inhibin-A in the FMF triple test reduced AUC and DR from 0.859 and 64.86% to 0.837 and 54.05%, the ΔAUC was not statistically significant. AUC and DR when adding inhibin-A to the FMF triple test were 0.814, 54.05% and the -0.045 reduction in AUC was statistically significant (p = 0.001). At a fixed 10% FPR, replacing PlGF with inhibin-A identified 1 (2.7%) additional pregnancy but missed 5 (13.5%) pregnancies which subsequently developed preterm PE identified by the FMF triple test. Adding inhibin-A missed 4 (10.8%) pregnancies and did not identify any additional pregnancies with preterm PE. Replacing PlGF by inhibin-A or adding inhibin-A as an additional biomarker in and to the FMF triple screening test for preterm PE does not improve screening performance and will fail to identify pregnancies that are currently identified by the FMF triple test.

Adverse pregnancy outcomes in women at increased risk of preterm pre-eclampsia on first-trimester combined screening.

Uteroplacental dysfunction may not only result in pre-eclampsia (PE) but also in preterm birth (PTB), small-for-gestational-age (SGA) birth and stillbirth. The aim of this study is to evaluate the positive predictive value (PPV) of first-trimester combined PE screening for all of these placenta-mediated adverse pregnancy outcomes. Retrospective cohort study. Tertiary referral maternity unit. A total of 13 211 singleton pregnancies. First-trimester combined screening for preterm PE using the Fetal Medicine Foundation (FMF) algorithm. Hypertensive disorders of pregnancy (HDP), PTB, SGA birth and stillbirth were combined to assess composite adverse and severe adverse pregnancy outcomes (CAPO and CAPO-S). The PPVs for CAPO and CAPO-S were calculated for women with a combined risk for preterm PE of ≥1 in 50 and ≥1 in 100. First-trimester combined screening identified 2215 women (16.8%) with a risk of ≥1 in 100 for preterm PE. The PPVs for a risk of ≥1 in 100 for CAPO and CAPO-S were 38.8% and 18.2%, respectively. The equivalent PPVs for a risk of ≥1 in 50 were 45.1% and 21.1%, respectively. Women identified at high risk of preterm PE are also at increased risk of other placenta-mediated adverse pregnancy outcomes, such as PTB, SGA birth and stillbirth. Women at high risk for preterm PE after first-trimester screening may benefit from a higher surveillance care pathway, with interventions to mitigate all the adverse outcomes associated with placental dysfunction.

Psychological Impact and Women's Evaluation of the First-Trimester Pre-Eclampsia Screening and Prevention: ASPRE Trial.

This study aims to extend the understanding of the psychological impact of the first-trimester pre-eclampsia (PE) screening on women identified as high risk for preterm PE. We examined the differences between low- vs. high-risk women throughout pregnancy in: symptoms of distress (anxiety, depression, physical and mental health, and worry), health behaviour changes, the experience of pregnancy, and attitudes towards PE screening. This study was nested within the ASPRE trial. Pregnant women were screened for preterm-PE risk status in the first trimester; the assessments were carried out before the screening, in the second and in the third trimester (n = 155 low-risk women and N = 82 high-risk women in the second trimester). The high-risk-for-PE women exhibited more depressive symptoms compared to the low-risk women in the second but not in the third trimester. No differences were observed between the two groups in other distress symptoms or in the women's evaluation of their experience of pregnancy. The high-risk group reported greater health behaviour changes compared to the low-risk group, but this was moderated by depression levels. Overall, pregnant women reported positive attitudes towards first-trimester PE screening, despite transient depressive symptoms. This study offers supportive evidence concerning the appropriateness of PE screening in ethical terms.

Effectiveness of the First Trimester Samrakshan Protocol for the Identification of Pregnant Women at High Risk for Preterm Pre-eclampsia.

Aim To determine the effectiveness of the first trimester Samrakshan protocol for the identification of pregnant women at high risk for preterm pre-eclampsia (PE). Methods Samrakshan uses a protocol that integrates routine first-trimester ultrasound assessment at 11 to 14 gestation weeks with the measurement of mean arterial blood pressure and mean uterine artery pulsatility index assessment to determine a customized risk for preterm PE and fetal growth restriction. Based on the risk assessment, pregnant women are classified as high or low risk. Results The protocol had a high specificity (90.4%, 95% CI: 89.4%, 91.2%) and negative predictive value (98.1%, 95% CI: 97.6%, 99%) for preterm PE. The odds ratio and positive likelihood ratio for preterm PE were 16.7 (95% CI: 12.3, 22.6) and 6.64 (95% CI: 5.77, 7.63), respectively. Conclusions The positive likelihood ratio and odds ratios indicate that pregnant women identified as high risk for preterm PE using the first-trimester protocol of Samrakshan are significantly more likely to develop preterm PE than low-risk women.

Impact of the Community-Integrated Model of Samrakshan on Perinatal Mortality and Morbidity in Guna District of Central India.

Aim The aim of this study was to assess the impact of the community-integrated Samrakshan model on perinatal mortality and morbidity in the Guna district of Central India Methods The trimester-specific Samrakshan protocols were used to screen pregnant women in the first, second, and third trimesters of pregnancy and to stratify risk for preterm preeclampsia (PE) and fetal growth restriction (FGR) in the screened population. Low-dose aspirin was recommended for women identified at high risk in the first trimester screening. Fifty training programs were conducted over the duration of the program for district health workers including Anganwadi workers, Accredited Social Health Activist (ASHA) personnel, and women and child health staff. Data on the development of PE, stages of FGR, preterm births (PTBs), birthweight, neonatal mortality, and perinatal mortality were collected and compared with the baseline year to assess trends. Results The program covered 168 Anganwadi centers and screened 1,021 women in the first trimester, 870 women in the second trimester, and 811 women in the third trimester of pregnancy from 2019 to 2022 and obtained details on childbirth outcomes from 1,219 women. PE did not occur in 71.58% of pregnant women identified at high risk for PE and occurred in only 2.37% of pregnant women identified at low risk for PE. The incidence of PE reduced from 9.36 to 1.61%, stage 1 FGR from 18.71 to 11.83%, PTB from 19.49 to 11.25%, and birthweight less than 2,500 g from 33.66 to 21.46% from 2019 to 2022. The neonatal mortality rate reduced from 26 to 7.47/1,000 live births from 2019 to 2022 and the perinatal mortality rate reduced from 33.90 to 18.87/1,000 childbirths from 2019 to 2022 in the Samrakshan program area at Guna. Conclusion The community-integrated model of Samrakshan in the Guna district has led to a significant reduction in perinatal morbidity and mortality in the program area.

Prioritizing Fetal Structural Abnormalities Over Risk for Pre-Eclampsia and Fetal Growth Restriction in the 20-24 Gestation Week Assessment in India: Missing the Woods for the Trees?

Aim To compare the magnitude of fetuses with congenital anomalies, pregnant women identified at high risk for preterm pre-eclampsia (PE) or with preterm PE, and with early fetal growth restriction (FGR) or high risk for FGR at the second trimester assessment at 20 to 24 weeks of gestation. Methods A standardized trimester-specific protocol that included clinical and demographic details, fetal biometry, estimated fetal weight (EFW), fetal abdominal circumference (FAC), mean arterial blood pressure and fetal Doppler studies was used to identify high risk for preterm PE and FGR. The Targeted Imaging for Fetal Anomalies (TIFFA) scan was used to identify congenital anomalies. In addition, 95% confidence intervals of the point estimates were derived, and the p -value was estimated to assess the statistical significance of the difference in proportions. Results Analysis of the data of 4,572 pregnant women screened between 20 and 24 gestation weeks showed a significantly lower prevalence ( p < 0.001) of congenital abnormalities (3.81%) compared to women diagnosed with early PE (2.71%) or with a high risk for PE (4.00%) and women (6.80%) with early FGR or at higher risk for fetal growth restriction with both EFW and FAC < 10th percentile. Conclusion The data on prevalence from Samrakshan show that the second-trimester assessment of pregnant women in India must expand its scope from the TIFFA scan to also focus on screening to identify women at high risk for preterm PE and FGR.

Does Aspirin Prescribed to Women Deemed High Risk for Preterm Pre-Eclampsia at 11–13+6 Weeks Gestation Affect the Prevalence of Small for Gestational Age Neonates?

(Abstracted from Aust N Z J Obstet Gynaecol 2021;61:347–353) Previous studies have reported that aspirin can be used to reduce the prevalence of both early-onset preeclampsia (ePET) and fetal growth restriction (FGR). The prevention of FGR would improve both pregnancy and infant outcomes and could also reduce costs to the health care system.

Maternal Cardiac Function in Women at High Risk for Pre-eclampsia Treated With 150 mg Aspirin or Placebo: An Observational Study

(BJOG. 2020;127:1018–1025) The Aspirin for Prevention of Preterm Pre-eclampsia (ASPRE) trial recently reported that aspirin (150 mg/d) may reduce the risk of preterm and early pre-eclampsia (PE) by 60% and 90%, respectively, in pregnant women screened in their first trimester. Although commonly used for the prevention and treatment of heart attacks or strokes in the general population, aspirin has also been shown to cause high blood pressure and exacerbate pre-existing heart failure. This may be explained in part by the inhibition of PGI2, a compensatory vasodilatory prostacyclin which results in vasoconstriction. In pregnant women at high risk for preterm PE, aspirin could lead to unfavorable cardiac outcomes. The aim of this study was to compare the hemodynamic effect of aspirin versus placebo in women at high-risk for preterm PE and to compare this effect in women at low risk versus high risk for developing this condition.

Use of Low Dos Aspirin in Women with Increased Risk of Preeclampsia

Introduction: The role of aspirin in the primary or secondary prevention of preeclampsia has beenthe subject of numerous studies and great controversy. Our aim reports on LDA usage rates bywomen with an increased PE risk, as well as on determinants and reasons given for use and non‐use. Material and Method: In this multicenter, double-blind, placebo-controlled trial, the currentstudy randomly assigned 2100 women with singleton pregnancies who were at high risk for pretermpreeclampsia to receive aspirin, at a dose of 150 mg per day, or placebo from 11 to 14 weeks ofgestation until 36 weeks of gestation. The primary outcome was delivery with preeclampsia before37 weeks of gestation. The analysis was performed according to the intention-to-treat principle.Results: Preterm preeclampsia occurred in 13 participants (1.6%) in the aspirin group, as comparedwith 35 (4.3%) in the placebo group (odds ratio in the aspirin group, 0.38; 95% confidence interval,0.20 to 0.74; P=0.004). Results were materially unchanged in a sensitivity analysis that took intoaccount participants who had withdrawn or were lost to follow-up. Conclusion: This randomizedtrial showed that among women with singleton pregnancies who were identified using first-trimesterscreening as being at high risk for preterm preeclampsia, the administration of aspirin at a dose of150 mg per day from 11 to 14 weeks of gestation until 36 weeks of gestation resulted in asignificantly lower incidence of preterm preeclampsia than that with placebo.

Maternal cardiac function in women at high risk for pre-eclampsia treated with 150mg aspirin or placebo: an observational study.

To compare maternal haemodynamics in women at low and high risk for preterm pre-eclampsia (PE), and between those at high risk who are randomised to aspirin or placebo. Prospective, longitudinal observational study. Maternity units in six UK hospitals. Women participating in the Aspirin for Prevention of Preterm Pre-eclampsia (ASPRE) trial. The population comprised three groups of women: low risk for preterm PE (n=1362), high risk for preterm PE treated with aspirin (n=208) and high risk for preterm PE on placebo (n=220). Women had four visits during pregnancy: 11-14, 19-24, 30-34, and 35-37weeks' gestation. Blood pressure was measured with a device validated for pregnancy, and PE and maternal haemodynamics were assessed with a bioreactance monitor at each visit. A multilevel linear mixed-effects analysis was performed to examine longitudinal changes of maternal haemodynamic variables, controlling for demographic characteristics, past medical history and medication use. Longitudinal changes of cardiac output (CO), mean arterial pressure (MAP), and peripheral vascular resistance (PVR). The low-risk group demonstrated the expected changes with an increase in CO and reduction in MAP and PVR, with a quadratic change across gestation. In contrast, the high-risk groups had a declining CO, and higher MAP and PVR during pregnancy. The administration of aspirin did not appear to affect maternal haemodynamics. Women screened as high risk for preterm PE have a pathological cardiac adaptation to pregnancy and the prophylactic use of aspirin (150mg oral daily from the first trimester) in this group may not alter this haemodynamic profile. In women at high risk of pre-eclampsia, prophylactic use of aspirin may not alter the impaired maternal cardiac adaptation.

From first-trimester screening to risk stratification of evolving pre-eclampsia in second and third trimesters of pregnancy: comprehensive approach.

Preeclampsia and associated hypertensive disorders of pregnancy represent a leading cause of global maternal and neonatal morbidity and mortality. Identification of women at high risk for developing preterm-preeclampsia and prophylaxis with low-dose aspirin has the potential to significantly reduce the rate of preterm-preeclampsia. In addition, risk assessment and monitoring of women in the second and third trimester of pregnancy, to aid in early detection of evolving disease, timely referral to specialist care, and active monitoring of women with confirmed or suspected preeclampsia is essential for improving maternal and neonatal outcomes. The angiogenesis-related biomarkers sFlt-1 and PlGF have been shown to have clinical value to aid in the prediction, diagnosis, and risk stratification of preeclampsia when used either alone or in combination with other risk factors. However, currently there is no consensus on the optimum strategy to link first trimester screening for preterm-preeclampsia with appropriate second and third trimester risk assessment strategies. This opinion paper will outline the current evidence for first trimester preeclampsia screening and prevention, as well as the evidence for various risk stratification approaches for detection of evolving preeclampsia through the second and third trimesters of pregnancy, and proposes a potential model integrating these tools. This article is protected by copyright. All rights reserved.

Samrakshan: An Indian Radiological and Imaging Association program to reduce perinatal mortality in India.

Context:India has a high perinatal mortality rate. The Indian Radiological and Imaging Association (IRIA) is supplementing efforts to address perinatal mortality in India through the Samrakshan program.Aims:To describe various elements of the Samrakshan program that aims to reduce perinatal mortality in India.Methods:Samrakshan focuses on two priority areas, preeclampsia (PE) and fetal growth restriction (FGR). Samrakshan aims at technical skill upgradation, specifically focused on improved interpretative ability, prognostic and therapeutic efficacy using Doppler studies, a free online learning platform and offline continuous medical educations (CMEs), building an evidence base from the program to develop policy and guidelines, and improving synergy with the RAKSHA program of IRIA and other fetal care stakeholders.Results:Two courses on Doppler studies focused on first trimester and third trimester, supplemented by case discussions and journal articles, have started on the online platform with 230 registrants. The first statewide CME was held at Indore. Samrakshan screening identified 10 (17.24%, 95% CI: 8.59, 29.43) women at high risk for preterm PE and 29 (50.00%, 95% CI 36.58, 63.42) women at high risk for FGR in the first trimester. Ten fetuses (7.63%, 95% CI: 3.72, 13.59) including 9 with stage 1 FGR were identified in the third-trimester screening.Conclusions:Samrakshan is a flagship program of IRIA that aims to reduce perinatal mortality in India through a synergistic, holistic approach that complements and supplements existing efforts in India.

Risk assessment for preterm preeclampsia in first trimester: Comparison of three calculation algorithms

ObjectiveTo better adjust the risk for preeclampsia, multifactorial models in first trimester of pregnancy have found the way in clinical practice. This study compares the available test algorithms. Study designIn a cross-sectional study between November 2013 and April 2016 we compared the tests results of three first trimester testing algorithms for preeclampsia in 413 women. Risk for preterm preeclampsia was calculated with three different algorithms: Preeclampsia Predictor™ Software by PerkinElmer (PERK), ViewPoint® Software by GE Healthcare (VP) and the online calculator of the Fetal Medicine Foundation (FMF).We analyzed the data descriptively and determined Cohen's Kappa to assess the agreement among the algorithms. ResultsVP classified 89(21.5%) women, PERK 43(10.4%) women and FMF 90 (21.8%) women as having high risk for preterm preeclampsia (<34 weeks of gestation for VP and PERK and <37 weeks of gestation for FMF). Agreement between tests ranged from moderate to substantial (PERK/VP: κ = 0.56, PERK/ FMF: κ = 0.50, and VP/ FMF: κ = 0.72). ConclusionThe three algorithms are similar but not equal. This may depend on chosen cut off, but also on test properties. This study cannot decide which algorithm is the best, but differences in results and cut offs should be taken into account.

Aspirin versus placebo in pregnancies at high risk for preterm pre-eclampsia.

A recent multicentre placebo-controlled trial by Rolnick etal. has indicated that taking 150 mg aspirin daily in women at high risk of pre-eclampsia reduced the incidence of the disease from 4.3% to 1.5% in comparison with placebo. Although the findings of this study are important, a high proportion of women withdrew their consent and not all safety outcomes have been reported. This journal watch article discusses the paper in more detail.

Aspirin Versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia

(N Engl J Med. 2017;377(7):613–622) Professional associations recommend the prophylactic use of low-dose aspirin (60 to 80 mg d) in pregnant women who are considered to be at high risk for preeclampsia. However, some studies suggest that aspirin started after 16 weeks of gestation does not have a significant benefit, and there remain major challenges in identifying women at high risk for this condition.

Aspirin Versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia

(Abstracted from N Engl J Med 2017;377:613–622) Since 1979, multiple studies have shown that low-dose aspirin in pregnancy can lower the occurrence of preeclampsia. Subsequent studies have shown that doses greater than 100 mg/d started before 16 weeks of gestation are most effective.

Aspirin for pregnancies at high risk for preterm pre-eclampsia.

Aspirin for pregnancies at high risk for preterm pre-eclampsia.

Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia

BackgroundPreterm preeclampsia is an important cause of maternal and perinatal death and complications. It is uncertain whether the intake of low-dose aspirin during pregnancy reduces the risk of preterm preeclampsia.MethodsIn this multicenter, double-blind, placebo-controlled trial, we randomly assigned 1776 women with singleton pregnancies who were at high risk for preterm preeclampsia to receive aspirin, at a dose of 150 mg per day, or placebo from 11 to 14 weeks of gestation until 36 weeks of gestation. The primary outcome was delivery with preeclampsia before 37 weeks of gestation. The analysis was performed according to the intention-to-treat principle.ResultsA total of 152 women withdrew consent during the trial, and 4 were lost to follow up, which left 798 participants in the aspirin group and 822 in the placebo group. Preterm preeclampsia occurred in 13 participants (1.6%) in the aspirin group, as compared with 35 (4.3%) in the placebo group (odds ratio in the aspirin group, 0.38; 95% confidence interval, 0.20 to 0.74; P=0.004). Results were materially unchanged in a sensitivity analysis that took into account participants who had withdrawn or were lost to follow-up. Adherence was good, with a reported intake of 85% or more of the required number of tablets in 79.9% of the participants. There were no significant between-group differences in the incidence of neonatal adverse outcomes or other adverse events.ConclusionsTreatment with low-dose aspirin in women at high risk for preterm preeclampsia resulted in a lower incidence of this diagnosis than placebo. (Funded by the European Union Seventh Framework Program and the Fetal Medicine Foundation; EudraCT number, 2013-003778-29; Current Controlled Trials number, ISRCTN13633058.)