Strategies for Prescribing Aspirin to Prevent Preeclampsia: A Cost-Effectiveness Analysis

Controversies and Clarifications Regarding the Role of Aspirin in Preeclampsia Prevention: A Focused Review

Preeclampsia is one of the leading causes of maternal and perinatal morbidity and mortality worldwide. In recent decades, many studies have evaluated different interventions in order to prevent the occurrence of preeclampsia. Among these, administration of low-dose aspirin from early pregnancy showed consistent evidence of its prophylactic role. In this article, we review the scientific literature on this topic, highlighting the rationale for aspirin use, who should be treated, the timing of initiation and cessation of therapy, the importance of proper dosing, and its role in the prevention of other adverse outcomes.

Preventing maternal morbidity and mortality from preeclampsia and eclampsia particularly in low- and middle-income countries

Preeclampsia (PE) is a complex heterogeneous disorder with overlapping clinical phenotypes that complicate diagnosis and management. Although several pathophysiological mechanisms have been proposed, placental dysfunction due to inadequate remodelling of uterine spiral arteries leading to mal-perfusion and syncytiotrophoblast stress is recognized as the unifying characteristic of early-onset PE. Placental overgrowth and or premature senescence are probably the causes of late-onset PE. The frequency of PE has increased over the last few decades due to population-wide increases in risk factors viz. obesity, diabetes, multifetal pregnancies and pregnancies at an advanced maternal age. Whilst multimodal tools with components comprising risk factors, biomarkers and sonography are used for predicting PE, aspirin is most effective in preventing early-onset PE. The incidence and clinical consequences of PE and eclampsia are influenced by socioeconomic and cultural factors, therefore management strategies should involve multi-sector partnerships to mitigate the adverse outcomes.

Aspirin for preeclampsia prevention in low- and middle-income countries: mind the gaps

Preeclampsia is a syndrome that continues to be a major contributor to maternal and neonatal mortality, especially in low-income countries. Low-dose aspirin reduces the risk of preeclampsia, but the mechanism is still unknown. Risk factors to identify women at risk of preeclampsia are based on clinical characteristics. Women identified as high-risk would benefit from aspirin treatment initiated, preferably at the end of the first trimester. Current efforts have largely focused on developing screening algorithms that incorporate clinical risk factors, maternal biomarkers, and uterine artery Doppler evaluated in the first trimester. However, most studies on preeclampsia are conducted in high-income settings, raising uncertainties about whether the information gained can be totally applied in low-resource settings. In low- and middle-income countries, lack of adequate antenatal care and late commencement of antenatal care visits pose significant challenges for both screening for preeclampsia and initiating aspirin treatment. Furthermore, the preventive effect of first-trimester screening based on algorithms and subsequent aspirin treatment is primarily seen for preterm preeclampsia, and reviews indicate minimal or no impact on reducing the risk of term preeclampsia. The lack of evidence regarding the effectiveness of aspirin in preventing term preeclampsia is a crucial concern, as 75% of women will develop this subtype of the syndrome. Regarding adverse outcomes, low-dose aspirin has been linked to a possible higher risk of postpartum hemorrhage, a condition as deadly as preeclampsia in many low- and middle-income countries. The increased risk of postpartum hemorrhage among women in low-income settings should be taken into consideration when discussing which pregnant women would benefit from the use of aspirin and the ideal aspirin dosage for preventing preeclampsia. In addition, women's adherence to aspirin during pregnancy is crucial for determining its effectiveness and complications, an aspect often overlooked in trials. In this review, we analyze the knowledge gaps that must be addressed to safely increase low-dose aspirin use in low- and middle-income countries, and we propose directions for future research.

Factors Associated with Guideline Concordant Clinician Counseling about Low-Dose Aspirin to Prevent Preeclampsia in Nulliparous Patients

OBJECTIVE

The primary aim of this study was to examine the United States Preventative Services Task Force (USPSTF) guidelines concordant low-dose aspirin (LDA) counseling and factors associated with counseling in nulliparous birthing individuals.

STUDY DESIGN

We conducted a retrospective cohort study of nulliparous birthing individuals who delivered between January 1, 2019 and June 30, 2020 and received prenatal care at the Duke High Risk Obstetrical Clinics (HROB). All nulliparous patients over 18 years old who established or transferred care to HROB by 16 weeks, 6 days were included in the analysis. We excluded patients with more than two previous first-trimester pregnancy losses, multiple gestation, a known contraindication to LDA, initiation of LDA prior to their prenatal care, or documented medical history of coagulation disorder. Bivariate associations between demographic/medical characteristics and our primary outcome, receipt of counseling (yes/no), were assessed using two-sample t-tests for continuous variables and chi-square or Fisher's exact test for categorical variables. Factors significantly associated with the primary outcome (p < 0.05) were entered into the multivariable logistic regression model.

RESULTS

Among 391 birthing individuals included in the final analysis cohort, 51.7% of eligible patients received guideline consistent LDA counseling. Factors associated with increased odds of LDA counseling were advanced maternal age (adjusted odds ratio [aOR]: 1.05, 95% confidence interval [CI]: 1.01-1.09), Black race compared with White race (aOR:1.75, 95% CI: 1.03-2.98), chronic hypertension (aOR: 4.17, 95% CI: 1.82-9.55), and obesity (aOR: 5.02, 95% CI: 3.12-8.08).

CONCLUSION

Approximately half of all nulliparous birthing individuals had appropriately documented LDA counseling. The USPSTF guidelines on LDA for preeclampsia risk reduction are complex, which may lead to ineffective provider adherence. Efforts to simplify guidelines and improve LDA counseling are vital to ensuring this low-cost, evidence-based preeclampsia prevention is used in a consistent and equitable manner.

KEY POINTS

· A total of 51.7% of eligible patients received guideline consistent LDA counseling.. · Advanced maternal age , body mass index > 30, Black race, and chronic hypertension associated with increased odds of counseling.. · Among patients most likely to be counseled, high numbers did not receive LDA counseling..

Low-dose aspirin for the prevention of preterm birth in nulliparous women: systematic review and meta-analysis

OBJECTIVE

The objective was to assess the efficacy and safety of low-dose aspirin for the prevention of preterm birth in nulliparous women.

DATA SOURCES

We searched PubMed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to June 2022.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared aspirin to placebo in nulliparous women were eligible.

METHODS

This study was reported in accordance with the PRISMA 2020 checklist. The primary outcomes of this study were the rates of preterm birth at less than 37 weeks and less than 34 weeks of gestation. The secondary outcomes included postpartum hemorrhage, placental abruption, cesarean section, any hypertensive disorder of pregnancy and small for gestational age. Relative risks with their 95% confidence intervals were calculated for analysis. Heterogeneity was assessed by Cochran's Q test and Higgins's I2. A random-effects model was used when I2 was > 50% to generate the RR and 95% CI; otherwise, a fixed-effects model was used. The risk of publication bias was assessed by funnel plots. We performed sensitivity analysis by sequentially omitting each included study to confirm the robustness of the analysis.

RESULTS

Seven studies with a total of 29,029 participants were included in this review. Six studies were assessed as having a low risk of bias or an unclear risk of bias, and one study was judged as having a high risk of bias. In nulliparous women, low-dose aspirin was associated with a significant reduction in the rate of preterm birth at less than 34 weeks of gestational age (RR 0.84,95% CI: 0.71-0.99; I2 = 0%; P = 0.04), but we did not observe a significant difference in the rate of preterm birth at less than 37 weeks of gestation (RR 0.96,95% CI: 0.90-1.02; I2 = 31%; P = 0.18). Low-dose aspirin was associated with a significant increase in the rates of postpartum hemorrhage (RR 1.32,95% CI: 1.14-1.54; I2 = 0%; P = 0.0003), placental abruption (RR 2.18,95% CI: 1.10-4.32; I2 = 16%; P = 0.02) and cesarean section (RR 1.053, 95% CI: 1.001-1.108; I2 = 0%; P = 0.05) in nulliparous women. We also did not observe a significant effect of low-dose aspirin on the rates of any hypertensive disorder of pregnancy (RR 1.05, 95% CI: 0.96-1.14; I2 = 9%; P = 0.28) or small for gestational age (RR 0.96, 95% CI: 0.91-1.02; I2 = 0%; P = 0.16) in nulliparous women. Funnel plots indicated that no significant publication bias existed in this meta-analysis. Except for preterm birth at less than 34 weeks of gestation, placental abruption and cesarean section, the sensitivity analysis showed similar results, which confirmed the robustness of this meta-analysis.

CONCLUSIONS

Low-dose aspirin might reduce the risk of preterm birth at less than 34 weeks of gestation in nulliparous women. The use of low-dose aspirin in nulliparous women increased the risk of postpartum hemorrhage and might increase the risk of placental abruption and cesarean section.

First trimester screening for pre-eclampsia and targeted aspirin prophylaxis: a cost-effectiveness cohort study

OBJECTIVE

Investigate cost-effectiveness of first trimester pre-eclampsia screening using the Fetal Medicine Foundation (FMF) algorithm and targeted aspirin prophylaxis in comparison with standard care.

DESIGN

Retrospective observational study.

SETTING

London tertiary hospital.

POPULATION

5957 pregnancies screened for pre-eclampsia using the National Institute for Health and Care Excellence (NICE) method.

METHODS

Differences in pregnancy outcomes between those who developed pre-eclampsia, term pre-eclampsia and preterm pre-eclampsia were compared by the Kruskal-Wallis and Chi-square tests. The FMF algorithm was applied retrospectively to the cohort. A decision analytic model was used to estimate costs and outcomes for pregnancies screened using NICE and those screened using the FMF algorithm. The decision point probabilities were calculated using the included cohort.

MAIN OUTCOME MEASURES

Incremental healthcare costs and QALY gained per pregnancy screened.

RESULTS

Of 5957 pregnancies, 12.8% and 15.9% were screen-positive for development of pre-eclampsia using the NICE and FMF methods, respectively. Of those who were screen-positive by NICE recommendations, aspirin was not prescribed in 25%. Across the three groups, namely, pregnancies without pre-eclampsia, term pre-eclampsia and preterm pre-eclampsia there was a statistically significant trend in rates of emergency caesarean (respectively 21%, 43% and 71.4%; P < 0.001), admission to neonatal intensive care unit (NICU) (5.9%, 9.4%, 41%; P < 0.001) and length of stay in NICU. The FMF algorithm was associated with seven fewer cases of preterm pre-eclampsia, cost saving of £9.06 and QALY gain of 0.00006/pregnancy screened.

CONCLUSIONS

Using a conservative approach, application of the FMF algorithm achieved clinical benefit and an economic cost saving.

Propensity score analysis of low-dose aspirin and bleeding complications in pregnancy

OBJECTIVE

Low-dose aspirin (LDA) has been shown to reduce the risk of preterm pre-eclampsia and it has been suggested that it should be recommended for all pregnancies. However, some studies have reported an association between LDA and an increased risk of bleeding complications in pregnancy. Our aim was to evaluate the risk of placental abruption and postpartum hemorrhage (PPH) in patients for whom their healthcare provider had recommended prophylactic aspirin.

METHODS

This multicenter cohort study included 72 598 singleton births at 19 hospitals in the USA, between January 2019 and December 2021. Pregnancies complicated by placenta previa/accreta, birth occurring at less than 24 weeks' gestation, multiple pregnancy or those with data missing for aspirin recommendation were excluded. Propensity scores were calculated using 20 features spanning sociodemographic factors, medical history, year and hospital providing care. The association between LDA recommendation and placental abruption or PPH was estimated by inverse-probability treatment weighting using the propensity scores.

RESULTS

We included 71 627 pregnancies in the final analysis. Aspirin was recommended to 6677 (9.3%) and was more likely to be recommended for pregnant individuals who were 35 years or older (P < 0.001), had a body mass index of 30 kg/m2 or higher (P < 0.001), had prepregnancy hypertension (P < 0.001) and who had a Cesarean delivery (P < 0.001). Overall, 1.7% of the study cohort (1205 pregnancies) developed preterm pre-eclampsia: 1.3% in the no-aspirin and 5.8% in the aspirin group. After inverse-probability weighting with propensity scores, aspirin was associated with increased risk of placental abruption (adjusted odds ratio (aOR), 1.44 (95% CI, 1.04-2.00)) and PPH (aOR, 1.21 (95% CI, 1.05-1.39)). The aOR translated to a number needed to harm with LDA of 79 (95% CI, 43-330) for PPH and 287 (95% CI, 127-3151) for placental abruption.

CONCLUSIONS

LDA recommendation in pregnancy was associated with increased risk for placental abruption and for PPH. Our results support the need for more research into aspirin use and bleeding complications in pregnancy before recommending it beyond the highest-risk pregnancies. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Aspirin in Pregnancy

Preeclampsia is associated with significant perinatal morbidity and mortality. Aspirin has been long purported and extensively studied for prevention of preeclampsia. For this reason, the U.S. Preventive Services Task Force, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine recommend its use in pregnancy for preeclampsia prevention in those at high risk. Yet, much controversy exists regarding optimal use in pregnancy with guidelines across global organizations varying. In this narrative review, we summarize the published literature related to the safety, optimal dose, and timing and duration of use of aspirin, as well as other indications for which aspirin has been studied in pregnancy.

Provider adherence to aspirin prophylaxis prescription guidelines for preeclampsia

OBJECTIVE

To evaluate provider adherence to aspirin prophylaxis prescription guidelines for patients at risk.

STUDY DESIGN

A retrospective chart review was performed at Henry Ford Health (HFH) between October 2015 and December 2020. In October 2015, low-dose aspirin was recommended for women who met high risk criteria for preeclampsia at HFH; in February 2019, aspirin recommendation expanded to include women who met either moderate or high-risk criteria. A total of 46,016 pregnancies occurred between Oct 2015 and Dec 2020 of which 15,167 (33.0%) met high and moderate risk criteria.

RESULTS

From the population at risk, 1,255 (8.3%) had a history of preeclampsia, 2,534 (16.7%) had a history of chronic hypertension, 1,418 (9.3%) had a history of diabetes, 7,470 (49.3%) were nulliparous, 4,038 (26.6%) were 35 years of age or older, 6,395 (42.2%) had a body mass index greater than 30 kg/m2, and 8,174 (54.5%) were African Americans. Only 630 out of 3,584 (17.6%) of women meeting the high-risk criteria for preeclampsia between Oct 2015 and Jan 2019 received low-dose aspirin and only 891 out of 5,874 (15.2%) of women meeting the high or moderate risk criteria for preeclampsia between Feb 2019 and Dec 2020 received low-dose aspirin prophylaxis.

CONCLUSION

Adherence to aspirin prophylaxis guidelines was low. Most urban healthcare systems serve diverse, high-risk populations with multiple comorbidities rendering many women at risk for preeclampsia. Educational efforts to improve provider knowledge regarding this important preventative measure are indicated. Recommendation for implementing universal aspirin in such high-risk populations should also be considered.

Low-dose aspirin therapy for the prevention of preeclampsia: time to reconsider our recommendations?

The American College of Obstetricians and Gynecologists recommends initiation of 81 mg of aspirin daily for women at risk of preeclampsia between 12 and 28 weeks' gestation, optimally before 16 weeks, with continuation until delivery. The World Health Organization recommends that 75 mg of aspirin should be initiated before 20 weeks of gestation for women at high risk of preeclampsia. Both the Royal College of Obstetricians and Gynaecologists and the National Institute of Health and Care Excellence quality statement on "Antenatal Assessment of Pre-eclampsia Risk" request that healthcare providers prescribe low-dose aspirin to pregnant women at increased risk of preeclampsia daily from 12 weeks of gestation. The Royal College of Obstetricians and Gynaecologists recommends 150 mg of aspirin daily, and the National Institute of Health and Care Excellence guidelines suggest risk stratification with a dosage of 75 mg for those at moderate risk of preeclampsia and 150 mg for those at high risk of preeclampsia. The International Federation of Gynecology and Obstetrics initiative on preeclampsia recommends 150 mg of aspirin to be initiated at 11 to 14+6 week's gestation and also proposes that 2 tablets of 81 mg is an acceptable alternative. Review of the available evidence suggests that both the dosage and timing of aspirin initiation is key to its effectiveness at reducing the risk of preeclampsia. Doses of >100 mg of aspirin daily initiated before 16 weeks' gestation seem to be most effective at reducing the risk of preeclampsia and thus dosages recommended by most major societies and organizations may not be effective. Randomized control trials examining 81 mg vs 162 mg of aspirin daily for the prevention of preeclampsia are required to assess the safety and efficacy of aspirin dosages available in the United States.

Low-Dose Aspirin during Pregnancy and Postpartum Bleeding

OBJECTIVE

This study aimed to investigate whether aspirin 81 mg daily for preeclampsia prevention is associated with increased risk of postpartum blood loss at the time of delivery.

STUDY DESIGN

This is a retrospective cohort study performed at a tertiary hospital from January 2018 to April 2021. Data were extracted from the electronic medical record. Patients prescribed low-dose aspirin (LDA) were compared with patients who were not. The primary outcome was a composite of postpartum blood loss, defined as: estimated blood loss (EBL) >1,000 mL, documentation of International Classification of Diseases-9/-10 codes for postpartum hemorrhage (PPH), or red blood cell (RBC) transfusion. Bivariate analysis, and unadjusted and adjusted logistic regression modeling were performed.

RESULTS

Among 16,980 deliveries, 1,922 (11.3%) were prescribed LDA. Patients prescribed LDA were more likely to be >35 years old, nulliparous, obese, taking other anticoagulants, or have diagnoses of diabetes, systemic lupus erythematosus, fibroids, or hypertensive disease of pregnancy. After adjusting for potential confounders, the significant association between LDA use and the composite did not persist (adjusted odds ratio [aOR]: 1.1, 95% confidence interval [CI]: 1.0-1.3) nor did the association between EBL > 1,000 mL (aOR: 1.0, 95% CI: 0.9-1.3) and RBC transfusion (aOR: 1.3, 95% CI: 0.9-1.7). The association between LDA and PPH remained significant (aOR: 1.3, 95% CI: 1.1-1.6). Patients who discontinued LDA <7 days prior to delivery had an increased risk of the postpartum blood loss composite compared discontinuation ≥7 days (15.0 vs. 9.3%; p = 0.03).

CONCLUSION

There may be an association between LDA use and increased risk of postpartum bleeding. This suggests that use of LDA outside the recommended guidelines should be cautioned and further investigation is needed to determine its ideal dosing and timing of discontinuation.

KEY POINTS

· There may be an association with LDA and an increased risk of postpartum bleeding.. · Patients who discontinued LDA less than 7 days prior to delivery had an increased rate of postpartum bleeding.. · Additional research is need to determine optimal LDA dose and timing of discontinuation..

The prevalence and perinatal repercussions of preeclampsia after the implementation of a prophylaxis protocol with aspirin

OBJECTIVES

To evaluate the prevalence and perinatal repercussions of preeclampsia (PE) after the implementation of a prophylaxis protocol with aspirin in singleton pregnancy at Maternity School of Federal University of Rio de Janeiro, Rio de Janeiro, Brazil (2015-2106).

METHODOLOGY

PE prevalence according to gestational age (GA) and the prevalence ratio (PR) between PE and prematurity, small for gestational age (SGA), and fetal death were calculated in patients assisted during 2015 and 2016.

RESULTS

PE occurred in 373(10.75%) of 3468 investigated cases, where PE < 37 weeks was of 2.79% and PE greater than 37 weeks was of 7.95%. A total of 413 (11.9%) prematurity cases, 320 SGA (9.22%), and 50 fetal deaths (1.44%) occurred. In the PE group, 97 premature newborns (PR 0.90) and 51 SGA (PR 1.16) were born, and two fetal deaths occurred (PR 7.46). Concerning PE < 37 weeks, 27 SGA cases (PR 1.42) and two fetal deaths (PR 2.62) were observed. Regarding PE greater than 37 weeks, 24 SGA (PR 1.09) were born, and no fetal deaths were observed. Our findings were compared to previously published results.

CONCLUSIONS

PE was significantly associated with SGA newborns, especially premature PE. Prescribing aspirin for PE prophylaxis based only on clinical risk factors in a real-life scenario does not appear to be effective but resulted in a PE screening and prophylaxis protocol review and update at ME/UFRJ.

Low-Dose Aspirin after ASPRE-More Questions Than Answers? Current International Approach after PE Screening in the First Trimester

Preeclampsia (PE) is a multi-factorial disorder of pregnancy, and it continues to be one of the leading causes of fetal and maternal morbidity and mortality worldwide. Aspirin is universally recommended for high-risk women to reduce preeclampsia risk. The purpose of this review is to summarize the recommendations of various scientific societies on predicting preeclampsia and their indications for the inclusion of acetylsalicylic acid (ASA) prophylaxis. Fourteen guidelines were compared. The recommended dose, screening method, and gestational age at the start of the test vary depending on the recommendation. The societies are inclined to recommend using increasingly higher doses (>75 mg) of ASA, with many encouraging doses from 100 mg upward. Most societies indicate that the optimal time for implementing aspirin is prior to 16 weeks' gestation. Following the publication of the Aspirin for Evidence-Based Preeclampsia Prevention (ASPRE) trial results and other papers evaluating the Fetal Medicine Foundation (FMF) screening model, a large number of societies have changed their recommendations from those based on risk factors alone to the ones based on the risk assessment proposed by the FMF. This allows for the detection of a high-risk pregnancy population in whom aspirin will be remarkably effective in preventing preterm PE, thereby decreasing maternal and fetal morbidity.

Assessment of CA-125 First-Trimester Values as a Potential Screening Marker for Pre-Eclampsia

Background: Pre-eclampsia is a major public health issue. Current screening methods are based on maternal characteristics and medical history, but complex predictive models combining different clinical and biochemical markers have been proposed. However, although their accuracy is high, the implementation of these models in clinical practice is not always feasible, especially in low- and middle-resource settings. CA-125 is a tumoral marker, accessible and cheap, with proven potential as a severity marker in the third trimester of pregnancy in pre-eclamptic women. Assessment of its use as a first-trimester marker is necessary. Methods: This observational study involved fifty pregnant women between 11 and 14 weeks of pregnancy. Clinical and biochemical markers (PAPP-A), known for their value in pre-eclampsia screening, were recorded for every patient as well as first-trimester value of CA-125 and third-trimester data regarding blood pressure and pregnancy outcome. Results: No statistical correlation between CA-125 and first-trimester markers was observed except with PAPP-A, with which it exhibited a positive correlation. Additionally, no correlation was made between it and third-trimester blood pressure or pregnancy outcomes. Conclusions: CA-125 first-trimester values do not represent a valuable marker for pre-eclampsia screening. Further research on identifying an accessible and cheap marker to improve pre-eclampsia screening in low- and middle-income settings is needed.

Economic Evaluation of Prenatal and Postpartum Care in Women With Gestational Diabetes and Hypertensive Disorders of Pregnancy: A Systematic Review

OBJECTIVES

This study aimed to summarize evidence on the economic outcomes of prenatal and postpartum interventions for the management of gestational diabetes mellitus and hypertensive disorders of pregnancy (HDP), assess the quality of each study, and identify research gaps that may inform future research.

METHODS

Electronic databases including PubMed/MEDLINE, Embase, the Cochrane Library, and Cochrane Central Register of Controlled Trials were searched from January 1, 2000, to October 1, 2021. Selected studies were included in narrative synthesis and extracted data were presented in narrative and tabular forms. The quality of each study was assessed using the Consolidated Health Economic Evaluation Reporting Standards and Consensus on Health Economic Criteria list.

RESULTS

Among the 22 studies identified through the systematic review, 19 reported favorable cost-effectiveness of the intervention. For prenatal management of HDP, home blood pressure monitoring was found to be cost-effective compared with in-person visits in improving maternal and neonatal outcomes. For postpartum care, regular screening for hypertension or metabolic syndrome followed by subsequent treatment was found to be cost-effective compared with no screening in women with a history of gestational diabetes mellitus or HDP.

CONCLUSIONS

Existing economic evaluation studies showed that prenatal home blood pressure monitoring and postpartum screening for hypertension or metabolic syndrome were cost-effective. Nevertheless, limitations in the approach of the current economic evaluations may dampen the quality of the evidence and warrant further investigation.

Low-dose aspirin to prevent preeclampsia and growth restriction in nulliparous women identified by uterine artery Doppler as at high risk of preeclampsia: A double blinded randomized placebo-controlled trial

INTRODUCTION

This trial evaluates whether daily low-dose aspirin initiated before 16 weeks of gestation can reduce preeclampsia and fetal growth restriction in nulliparous women identified by first-trimester uterine artery Dopplers as at high risk of preeclampsia.

METHODS

This randomized, blinded, placebo-controlled, parallel-group trial took place in 17 French obstetric departments providing antenatal care. Pregnant nulliparous women aged ≥ 18 years with a singleton pregnancy at a gestational age < 16 weeks of gestation with a lowest pulsatility index ≥ 1.7 or a bilateral protodiastolic notching for both uterine arteries on an ultrasound performed between 11+0 and 13+6 weeks by a certified sonographer were randomized at a 1:1 ratio to 160 mg of low-dose aspirin or to placebo to be taken daily from inclusion to their 34th week of gestation. The main outcome was preeclampsia or a birthweight ≤ 5th percentile. Other outcomes included preeclampsia, severe preeclampsia, preterm preeclampsia, preterm delivery before 34 weeks, mode of delivery, type of anesthesia, birthweight ≤ 5th percentile and perinatal death.

RESULTS

The trial was interrupted due to recruiting difficulties. Between June 2012 and June 2016, 1104 women were randomized, two withdrew consent, and two had terminations of pregnancies. Preeclampsia or a birthweight ≤ 5th percentile occurred in 88 (16.0%) women in the low-dose aspirin group and in 79 (14.4%) in the placebo group (proportion difference 1.6 [-2.6; 5.9] p = 0.45). The two groups did not differ significantly for the secondary outcomes.

CONCLUSION

Low-dose aspirin was not associated with a lower rate of either preeclampsia or birthweight ≤ 5th percentile in women identified by their first-trimester uterine artery Doppler as at high risk of preeclampsia.

TRIAL REGISTRATION

(NCT0172946).

Standardizing Screening for Preeclampsia Risk Factors to Improve Prescribing of Low-Dose Aspirin

ABSTRACT

Preeclampsia is a serious health condition and leading cause of perinatal and neonatal morbidity and mortality. Research supports the use of low-dose aspirin therapy to prevent preeclampsia in high-risk pregnant people. This quality improvement project outlines the implementation of a preeclampsia risk screen in the electronic health record to ensure standardized screening for, and provision of, low-dose aspirin therapy consistent with professional guidelines. Two thousand three hundred seventy-one patients were seen between March and November 2020 at 13 OB/GYN and family practice offices at a large health system in our state. Provider screening and prescribing rates were evaluated at the first prenatal visit, and at 3-month intervals using an analytics dashboard built in the EHR. In the first 3 months after rollout visits at all offices in our system (March to May 2020), the average screening rate during first prenatal visits at all offices was 74.2% (n = 561), 41% (n = 230) had a positive screen, and 81.3% (n = 187) of those who screened high risk were prescribed aspirin as recommended. At 9 months after rollout, the screening rate during first prenatal visits at all offices improved to 95.6% (n = 782), 39.6% (n = 310) of those screened, screened positive, and 97.1% (n = 301) were prescribed low-dose aspirin therapy appropriately.

Cost-effectiveness analysis of implementing screening on preterm pre-eclampsia at first trimester of pregnancy in Germany and Switzerland

Objective

To assess the cost-effectiveness of preterm preeclampsia (PE) screening versus routine screening based on maternal characteristics in Germany and Switzerland.

Methods

A health economic model was used to analyse the cost-effectiveness of PE screening versus routine screening based on maternal characteristics. The analysis was conducted from the healthcare perspective with a time horizon of one year from the start of pregnancy. The main outcome measures were incremental health care costs and incremental costs per PE case averted.

Results

The incremental health care costs for PE screening versus routine screening per woman were €14 in Germany, and -CHF42 in Switzerland, the latter representing cost savings. In Germany, the incremental costs per PE case averted were €3,795. In Switzerland, PE screening was dominant. The most influential parameter in the one-way sensitivity analysis was the cost of PE screening (Germany) and the probability of preterm PE in routine screening (Switzerland). In Germany, at a willingness-to-pay for one PE case avoided of €4,200, PE screening had a probability of more than 50% of being cost-effective compared to routine screening. In Switzerland, at a willingness-to-pay of CHF0, PE screening had a 78% probability of being the most cost-effective screening strategy.

Conclusion

For Switzerland, PE screening is expected to be cost saving in comparison to routine screening. For Germany, the additional health care costs per woman were expected to be €14. Future cost-effectiveness studies should be conducted with a longer time horizon.

Directive clinique no 426 : Troubles hypertensifs de la grossesse : Diagnostic, prédiction, prévention et prise en charge

OBJECTIF

La présente directive a été élaborée par des fournisseurs de soins de maternité en obstétrique et en médecine interne. Elle aborde le diagnostic, l'évaluation et la prise en charge des troubles hypertensifs de la grossesse, la prédiction et la prévention de la prééclampsie ainsi que les soins post-partum des femmes avec antécédent de trouble hypertensif de la grossesse.

POPULATION CIBLE

Femmes enceintes. BéNéFICES, RISQUES ET COûTS: La mise en œuvre des recommandations de la présente directive devrait réduire l'incidence des troubles hypertensifs de la grossesse, en particulier la prééclampsie, et des issues défavorables associées. DONNéES PROBANTES: La revue exhaustive de la littérature a été mise à jour en tenant compte des nouvelles données probantes jusqu'en décembre 2020 et en suivant la même méthodologie que pour la précédente directive de la Société des obstétriciens et gynécologues du Canada (SOGC) sur les troubles hypertensifs de la grossesse. La recherche s'est limitée aux articles publiés en anglais ou en français. Les recommandations relatives aux traitements s'appuient d'abord sur les essais cliniques randomisés et les revues systématiques (lorsque disponibles), ainsi que sur l'évaluation des résultats cliniques substantiels chez les mères et les bébés. MéTHODES DE VALIDATION: Les auteurs se sont entendus sur le contenu et les recommandations par consensus et ont répondu à l'examen par les pairs du comité de médecine fœto-maternelle de la SOGC. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique d'évaluation, de développement et d'évaluation (GRADE) et se sont gardé l'option de désigner certaines recommandations par la mention « bonne pratique ». Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication.

PROFESSIONNELS CIBLES

Tous les fournisseurs de soins de santé (obstétriciens, médecins de famille, sages-femmes, infirmières et anesthésistes) qui prodiguent des soins aux femmes avant, pendant ou après la grossesse.

RECOMMANDATIONS

Guideline No. 426: Hypertensive Disorders of Pregnancy: Diagnosis, Prediction, Prevention, and Management

OBJECTIVE

This guideline was developed by maternity care providers from obstetrics and internal medicine. It reviews the diagnosis, evaluation, and management of the hypertensive disorders of pregnancy (HDPs), the prediction and prevention of preeclampsia, and the postpartum care of women with a previous HDP.

TARGET POPULATION

Pregnant women.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in these guidelines may reduce the incidence of the HDPs, particularly preeclampsia, and associated adverse outcomes.

EVIDENCE

A comprehensive literature review was updated to December 2020, following the same methods as for previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines, and references were restricted to English or French. To support recommendations for therapies, we prioritized randomized controlled trials and systematic reviews (if available), and evaluated substantive clinical outcomes for mothers and babies.

VALIDATION METHODS

The authors agreed on the content and recommendations through consensus and responded to peer review by the SOGC Maternal Fetal Medicine Committee. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, along with the option of designating a recommendation as a "good practice point." See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).The Board of the SOGC approved the final draft for publication.

INTENDED USERS

All health care providers (obstetricians, family doctors, midwives, nurses, and anesthesiologists) who provide care to women before, during, or after pregnancy.

RECOMMENDATIONS

Early cost-effectiveness analysis of screening for preeclampsia in nulliparous women: A modelling approach in European high-income settings

Background

Preeclampsia causes substantial maternal and perinatal morbidity and mortality and significant societal economic impact. Effective screening would facilitate timely and appropriate prevention and management of preeclampsia.

Objectives

To develop an early cost-effectiveness analysis to assess both costs and health outcomes of a new screening test for preeclampsia from a healthcare payer perspective, in the United Kingdom (UK), Ireland, the Netherlands and Sweden.

Methods

A decision tree over a 9-month time horizon was developed to explore the cost-effectiveness of the new screening test for preeclampsia compared to the current screening strategy. The new test strategy is being developed so that it can stratify healthy low risk nulliparous women early in pregnancy to either a high-risk group with a risk of 1 in 6 or more of developing preeclampsia, or a low-risk group with a risk of 1 in 100 or less. The model simulated 25 plausible scenarios in a hypothetical cohort of 100,000 pregnant women, in which the sensitivity and specificity of the new test were varied to set a benchmark for the minimum test performance that is needed for the test to become cost-effective. The input parameters and costs were mainly derived from published literature. The main outcome was incremental costs per preeclampsia case averted, expressed as an incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were conducted to assess uncertainty.

Results

Base case results showed that the new test strategy would be more effective and less costly compared to the current situation in the UK. In the Netherlands, the majority of scenarios would be cost-effective from a threshold of €50,000 per preeclampsia case averted, while in Ireland and Sweden, the vast majority of scenarios would be considered cost-effective only when a threshold of €100,000 was used. In the best case analyses, ICERs were more favourable in all four participating countries. Aspirin effectiveness, prevalence of preeclampsia, accuracy of the new screening test and cost of regular antenatal care were identified as driving factors for the cost-effectiveness of screening for preeclampsia.

Conclusion

The results indicate that the new screening test for preeclampsia has potential to be cost-effective. Further studies based on proven accuracy of the test will confirm whether the new screening test is a cost-effective additional option to the current situation.

Effectiveness of Different Algorithms and Cut-off Value in Preeclampsia First Trimester Screening

Results

For the cut-off point >1 : 150, 86 women at an increased risk of eo-PE using algorithm 1 were identified. Of these 86 patients, 83 (96%) were identified using algorithm 2, 62 (72%) using algorithm 3, and 60 (69%) using algorithm 4. In addition, it was demonstrated that between 21% and 29% of women at a low risk of eo-PE could be given acetylsalicylic acid if a screening test was used that did not account for PlGF.

Conclusions

In order to provide the highest level of health care to pregnant women, it is extremely important that full screening for eo-PE should be ensured. The cheapest algorithm based only on MAP and UtPI resulted in our patients being unnecessarily exposed to complications.

When to give aspirin to prevent preeclampsia: application of Bayesian decision theory

BACKGROUND

There is good evidence that first-trimester assessment of the risk for preterm preeclampsia and treatment of the high-risk group with aspirin reduces the incidence of preterm preeclampsia. Furthermore, there is evidence that aspirin is associated with an increased risk of maternal and neonatal hemorrhagic complications. Against this background, there are ongoing debates whether aspirin should be recommended for all women or to a subpopulation of women predicted to be at increased risk of developing preeclampsia. Moreover, if a strategy of the prediction and prevention of preterm preeclampsia is to be used, what method should be used for the prediction, and what risk cutoff should be used to decide on who to treat?

OBJECTIVE

This study aimed to compare the policies of universal treatment, stratified treatment, and no treatment with aspirin.

STUDY DESIGN

Decisions about aspirin prophylaxis were considered from the perspective of the Bayesian decision theory. Using this approach, the treatment policies were evaluated for risks of preterm preeclampsia, effects of aspirin, and trade-offs between the harms and benefits of the treatment. Evidence on the risk of preterm preeclampsia was taken from the Screening programme for pre-eclampsia study, which was a first-trimester screening study for the prediction of preeclampsia. Evidence of the effect of aspirin was taken from the Aspirin for Evidence-Based Preeclampsia Prevention trial, which was a trial of aspirin vs placebo in the prevention of preterm preeclampsia. The trade-off between the benefits and harms of aspirin was specified by addressing the question, "What is the maximum number of women that should be treated to prevent 1 case of preterm preeclampsia?" The number can be considered as an exchange rate between the harms and benefits of using aspirin to prevent preterm PE. Given the uncertainty about the harms associated with aspirin, the treatment policies were compared across a wide range of exchange rates.

RESULTS

For exchange rates between 10 and 1000 women treated with aspirin to prevent 1 case of preterm preeclampsia, the net benefit achieved from the risk assessment and targeted treatment of women at high risk of preterm preeclampsia was higher than that from women with no treatment or women with universal treatment with aspirin.

CONCLUSION

Universal treatment with aspirin should be avoided. Risk-based screening should be used, and the cutoff for taking aspirin should be determined from the consideration of the trade-off between the benefits and harms and detection, false-positive, and screen-positive rates.

Toward personalized management of chronic hypertension in pregnancy

Chronic hypertension complicates 1% to 2% of pregnancies, and it is increasingly common. Women with chronic hypertension are an easily recognized group who are in touch with a wide variety of healthcare providers before, during, and after pregnancy, mandating that chronic hypertension in pregnancy be within the scope of many practitioners. We reviewed recent data on management to inform current care and future research. This study is a narrative review of published literature. Compared with normotensive women, women with chronic hypertension are at an increased risk of maternal and perinatal complications. Women with chronic hypertension who wish to be involved in their care can do by measuring blood pressure at home. Accurate devices for home blood pressure monitoring are now readily available. The diagnostic criteria for superimposed preeclampsia remain problematic because most guidelines continue to include deteriorating blood pressure control in the definition. It has not been established how angiogenic markers may aid in confirmation of the diagnosis of superimposed preeclampsia when suspected, over and above information provided by routinely available clinical data and laboratory results. Although chronic hypertension is a strong risk factor for preeclampsia, and aspirin decreases preeclampsia risk, the effectiveness specifically among women with chronic hypertension has been questioned. It is unclear whether calcium has an independent effect in preeclampsia prevention in such women. Treating hypertension with antihypertensive therapy halves the risk of progression to severe hypertension, thrombocytopenia, and elevated liver enzymes, but a reduction in preeclampsia or serious maternal complications has not been observed; however, the lack of evidence for the latter is possibly owing to few events. In addition, treating chronic hypertension neither reduces nor increases fetal or newborn death or morbidity, regardless of the gestational age at which the antihypertensive treatment is started. Antihypertensive agents are not teratogenic, but there may be an increase in malformations associated with chronic hypertension itself. At present, blood pressure treatment targets used in clinics are the same as those used at home, although blood pressure values tend to be inconsistently lower at home among women with hypertension. Although starting all women on the same antihypertensive medication is usually effective in reducing blood pressure, it remains unclear whether there is an optimal agent for such an approach or how best to use combinations of antihypertensive medications. An alternative approach is to individualize care, using maternal characteristics and blood pressure features beyond blood pressure level (eg, variability) that are of prognostic value. Outcomes may be improved by timed birth between 38 0/7 and 39 6/7 weeks' gestation based on observational literature; of note, confirmatory trial evidence is pending. Postnatal care is facilitated by the acceptability of most antihypertensives (including angiotensin-converting enzymes inhibitors) for use in breastfeeding. The evidence base to guide the care of pregnant women with chronic hypertension is growing and aligning with international guidelines. Addressing outstanding research questions would inform personalized care of chronic hypertension in pregnancy.

Prevention of preeclampsia with aspirin

Preeclampsia is defined as hypertension arising after 20 weeks of gestational age with proteinuria or other signs of end-organ damage and is an important cause of maternal and perinatal morbidity and mortality, particularly when of early onset. Although a significant amount of research has been dedicated in identifying preventive measures for preeclampsia, the incidence of the condition has been relatively unchanged in the last decades. This could be attributed to the fact that the underlying pathophysiology of preeclampsia is not entirely understood. There is increasing evidence suggesting that suboptimal trophoblastic invasion leads to an imbalance of angiogenic and antiangiogenic proteins, ultimately causing widespread inflammation and endothelial damage, increased platelet aggregation, and thrombotic events with placental infarcts. Aspirin at doses below 300 mg selectively and irreversibly inactivates the cyclooxygenase-1 enzyme, suppressing the production of prostaglandins and thromboxane and inhibiting inflammation and platelet aggregation. Such an effect has led to the hypothesis that aspirin could be useful for preventing preeclampsia. The first possible link between the use of aspirin and the prevention of preeclampsia was suggested by a case report published in 1978, followed by the first randomized controlled trial published in 1985. Since then, numerous randomized trials have been published, reporting the safety of the use of aspirin in pregnancy and the inconsistent effects of aspirin on the rates of preeclampsia. These inconsistencies, however, can be largely explained by a high degree of heterogeneity regarding the selection of trial participants, baseline risk of the included women, dosage of aspirin, gestational age of prophylaxis initiation, and preeclampsia definition. An individual patient data meta-analysis has indicated a modest 10% reduction in preeclampsia rates with the use of aspirin, but later meta-analyses of aggregate data have revealed a dose-response effect of aspirin on preeclampsia rates, which is maximized when the medication is initiated before 16 weeks of gestational age. Recently, the Aspirin for Evidence-Based Preeclampsia Prevention trial has revealed that aspirin at a daily dosage of 150 mg, initiated before 16 weeks of gestational age, and given at night to a high-risk population, identified by a combined first trimester screening test, reduces the incidence of preterm preeclampsia by 62%. A secondary analysis of the Aspirin for Evidence-Based Preeclampsia Prevention trial data also indicated a reduction in the length of stay in the neonatal intensive care unit by 68% compared with placebo, mainly because of a reduction in births before 32 weeks of gestational age with preeclampsia. The beneficial effect of aspirin has been found to be similar in subgroups according to different maternal characteristics, except for the presence of chronic hypertension, where no beneficial effect is evident. In addition, the effect size of aspirin has been found to be more pronounced in women with good compliance to treatment. In general, randomized trials are underpowered to investigate the treatment effect of aspirin on the rates of other placental-associated adverse outcomes such as fetal growth restriction and stillbirth. This article summarizes the evidence around aspirin for the prevention of preeclampsia and its complications.

Estimated Prevalence of Risk Factors for Preeclampsia Among Individuals Giving Birth in the US in 2019

IMPORTANCE

Low-dose aspirin (LDA) is one of the few evidence-based interventions for preventing preeclampsia, which is a leading cause of maternal or fetal morbidity and mortality. Current guidelines recommend LDA based on the presence of risk factors for preeclampsia, but the population-based prevalence of these factors is unknown.

OBJECTIVE

To estimate population-level prevalence of preeclampsia risk factors used in prophylactic LDA guidelines for pregnant patients and the association of these risk factors with reported rates of pregnancy-related hypertension.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted using National Center for Health Statistics birth certificate data to describe the frequency of pregnant individuals with moderate to high-risk factors for preeclampsia and pregnancy-related hypertension rates. The study used all birth records in the United States for the 2019 calendar year.

EXPOSURES

Documentation of preeclampsia risk factors: multifetal gestation, pregestational diabetes, chronic hypertension (high-risk factors) and nulliparity, a body mass index greater than 30, African American race, a maternal age 35 years or older, an interval of more than 10-years since last birth, and having low socioeconomic status (moderate risk factors).

MAIN OUTCOMES AND MEASURES

Prevalence of each risk factor alone and in combinations leading to a recommendation for LDA; incidence of pregnancy-related hypertension by risk factor and combinations of risk factors.

RESULTS

There were 3 695 019 pregnancies in 2019, including 528 778 with no risk factors, 169 540 with 1 or more high-risk factors, and 2 996 701 with 1 or more moderate-risk factors. The mean (SD) of the cohort was 29.1 (5.8) years. Multifetal gestation was the most common high-risk factor and found in 123 995 pregnancies (3.4%), and low socioeconomic status was the most common moderate-risk factor and present in 1 732 729 pregnancies (46.9%). Based on 2021 criteria (a single high- or moderate-risk factors for preeclampsia), 3 166 241 pregnant patients (85.7%) were eligible for LDA. The incidence of pregnancy-related hypertension increased with the number of moderate-risk factors. The 2021 guidelines suggest considering or recommend LDA in 92.3% of pregnancies diagnosed with pregnancy-related hypertension.

CONCLUSIONS AND RELEVANCE

These data support the recently published guidelines and suggest further simplified guidelines recommending LDA to patients with any single moderate-risk factors.

Cost-effectiveness analysis of a model of first-trimester prediction and prevention of preterm pre-eclampsia compared with usual care

OBJECTIVES

Pre-eclampsia (PE) causes substantial maternal and neonatal mortality and morbidity. In addition to the personal impact on women, children and their families, PE has a significant economic impact on our society. Recent research suggests that a first-trimester multivariate model is highly predictive of preterm (< 37 weeks' gestation) PE and can be combined successfully with targeted prophylaxis (low-dose aspirin), resulting in an 80% reduction in prevalence of disease. The aim of this study was to examine the potential health outcomes and cost implications following introduction of first-trimester prediction and prevention of preterm PE within a public healthcare setting, compared with usual care, and to conduct a cost-effectiveness analysis to inform health-service decisions regarding implementation of such a program.

METHODS

A decision-analytic model was used to compare usual care with the proposed first-trimester screening intervention within the obstetric population (n = 6822) attending two public hospitals within a metropolitan district health service in New South Wales, Australia, between January 2015 and December 2016. The model, applied from early pregnancy, included exposure to a variety of healthcare professionals and addressed type of risk assessment (usual care or first-trimester screening) and use of (compliance with) low-dose aspirin prescribed prophylactically for prevention of PE. All pathways culminated in six possible health outcomes, ranging from no PE to maternal death. Results were presented as the number of cases of PE gained/avoided and the incremental increase/decrease in economic costs arising from the intervention compared with usual care. Significant assumptions were tested in sensitivity/uncertainty analyses.

RESULTS

The intervention produced, across all gestational ages, 31 fewer cases of PE and reduced aggregate economic health-service costs by 1 431 186 Australian dollars over the 2-year period. None of the tested iterations of uncertainty analyses reported additional cases of PE or higher economic costs. The new intervention based on first-trimester screening dominated usual care.

CONCLUSION

This cost-effectiveness analysis demonstrated a reduction in prevalence of preterm PE and substantial cost savings associated with a population-based program of first-trimester prediction and prevention of PE, and supports implementation of such a policy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prospective evaluation of first-trimester screening strategy for preterm pre-eclampsia and its clinical applicability in China

OBJECTIVES

To evaluate, in a Chinese population, the performance of a screening strategy for preterm pre-eclampsia (PE) using The Fetal Medicine Foundation (FMF)'s competing-risks model and to explore its clinical applicability in mainland China.

METHODS

This was a prospective, multicenter, observational cohort study including 10 899 women with singleton pregnancy who sought prenatal care at one of 13 hospitals, located in seven cities in mainland China, between 1 December 2017 and 30 December 2019. Mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and maternal serum levels of placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 to 13 + 6 weeks' gestation were measured and converted into multiples of the median using Chinese reference ranges. Individualized risk for preterm PE was calculated using the FMF algorithm. Prior risk was calculated based on maternal demographic characteristics and obstetric history. We evaluated the efficiency of the screening strategy using various combinations of biomarkers and analyzed its predictive performance for a composite of placenta-associated adverse pregnancy outcomes, including PE, placental abruption, small-for-gestational age (SGA) and preterm birth, at fixed false-positive rates for preterm PE.

RESULTS

We identified 312 pregnancies that developed PE, of which 117 cases were diagnosed as preterm PE (< 37 weeks' gestation). There were 386 pregnancies complicated by severe composite placenta-associated adverse outcome, including preterm PE, 146 cases of severe SGA (birth weight < 3^rd percentile) neonate, 61 cases with placental abruption and 109 cases of early preterm birth < 34 gestational weeks. The triple-marker model containing biomarkers MAP, UtA-PI and PAPP-A achieved, at fixed false-positive rates of 10%, 15% and 20%, detection rates for preterm PE of 65.0%, 72.7% and 76.1%, respectively, and detection rates for severe composite placenta-associated adverse outcome of 34.7%, 41.7% and 46.4%, respectively. Replacing PAPP-A with PlGF or adding PlGF to the model did not improve the performance. Of women screening positive for preterm PE at a fixed 5% false-positive rate, an estimated 30% developed at least one placenta-associated adverse pregnancy outcome, including PE, placental abruption, SGA (birth weight < 10^th percentile) and preterm birth < 37 weeks.

CONCLUSIONS

The FMF competing-risks model for preterm PE was found to be effective in screening a mainland Chinese population. Women who screened positive for preterm PE had increased risk for other placenta-associated pregnancy complications. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Cost-utility of a first-trimester screening strategy versus the standard of care for nulliparous women to prevent pre-term pre-eclampsia in Belgium

OBJECTIVES

To assess the cost-effectiveness of the Fetal Medicine Foundation (FMF) combined first-trimester pre-eclampsia (PE) screening algorithm, coupled with low-dose aspirin treatment in high-risk patients, compared to the standard of care (SOC; screening based on maternal risk factors) for nulliparous pregnancies in Belgium.

STUDY DESIGN

A decision analytic model was used to estimate the costs and outcomes for patients screened using the SOC and for those using the FMF screening algorithm, from the Belgian payers' perspective. Where possible, the probabilities and associated costs at each decision point were calculated based on published literature and public databases.

MAIN OUTCOME MEASURES

Cost-effectiveness was assessed using an incremental cost-effectiveness ratio. One-way sensitivity analyses were performed to assess the impact of independent variations in each model parameter. A probabilistic sensitivity analysis was used to estimate the impact of the overall uncertainty of the model on the estimated cost-effectiveness.

RESULTS

Considering an estimated 51,309 pregnancies in nulliparous women in Belgium per year, the FMF screening algorithm resulted in fewer cases of pre-term PE compared with the SOC (479 versus 816 cases) and a cost saving of €28.67 per patient. The outcome in quality-adjusted life-years was similar for both screening approaches (FMF screening algorithm 1.8521 versus SOC 1.8518). The FMF screening algorithm was cost-saving and more effective in 99.4% of simulations.

CONCLUSIONS

The FMF screening algorithm coupled with early intervention using low-dose aspirin has the potential to prevent an additional 337 cases of pre-term PE per year compared with the current SOC in this population, along with a cost saving.

Low-dose aspirin in pregnancy: who? when? how much? and why?

PURPOSE OF REVIEW

The use of low dose aspirin (LDA) has become routine in prenatal care for a variety of diagnoses, most importantly in women with a history of preeclampsia and associated poor pregnancy outcomes. Although LDA is currently indicated in patients considered to be at risk for development of preeclampsia, optimal dosing, timing of treatment initiation, and persons of benefit are under investigation. Several studies have also looked at LDA treatment and its effect on other maternal and fetal outcomes. This review summarizes the current guidelines for the use of LDA, incorporating the most recent research findings, and offers possible future implications of LDA treatment.

RECENT FINDINGS

Over 10 years ago, the American College of Obstetricians and Gynecologists, the World Health Organization, and the United States Preventive Service Task Force began publishing guidelines focused on the use of LDA in pregnancy. Since the release of these guidelines, several large studies have re-evaluated the use of LDA with a focus on initiation of treatment and dosing. The combined results of these studies suggest a decreased rate of preeclampsia at aspirin doses >100 mg when treatment is initiated prior to 16 weeks of gestation.

SUMMARY

Overall, early initiation of LDA has been shown to decrease the development of preeclampsia in patients considered at increased risk. Current literature suggests increasing the recommended dose to >100 mg to optimize these risk reductions. Although LDA use seems promising for other outcomes like preterm delivery and intrauterine growth restriction, further studies to strengthen recommendations are warranted.

Pre-eclampsia: Universal Screening or Universal Prevention for Low and Middle-Income Settings?

Pre-eclampsia (PE) is a severe disorder that affects up to 8% of all pregnancies and represents an important cause of maternal and perinatal morbidity and mortality. The screening of the disease is a subject of studies, but the complexity and uncertainties regarding its etiology make this objective a difficult task. In addition, the costs related to screening protocols, the heterogeneity of the most affected populations and the lack of highly effective prevention methods reduce the potential of current available algorithms for screening. Thus, the National Specialized Commission of Hypertension in Pregnancy of the Brazilian Association of Gynecology and Obstetrics Federation (Febrasgo, in the Portuguese acronym) (NSC Hypertension in Pregnancy of the Febrasgo) considers that there are no screening algorithms to be implemented in the country to date and advocates that Aspirin and calcium should be widely used.

Aspirin use during pregnancy and the risk of bleeding complications: a Swedish population-based cohort study

BACKGROUND

Aspirin is offered to pregnant women to prevent preeclampsia, a severe obstetrical complication. Large studies of nonpregnant populations have consistently shown that aspirin prophylaxis increases the risk of hemorrhagic complications. However, there have not been any population-based studies investigating this in a pregnant population.

OBJECTIVE

This study aimed to investigate whether aspirin use during pregnancy is associated with an increased risk of bleeding complications.

STUDY DESIGN

We performed a register-based cohort study using the Swedish Pregnancy Register wherein we examined 313,624 women giving birth between January 2013 and July 2017. Logistic regression was used to assess the risk of antepartum, intrapartum, and postpartum hemorrhage. A propensity score and inverse probability treatment weighting was used to generate an odds ratio that corrects for differences in baseline characteristics.

RESULTS

Aspirin use was registered in 4088 (1.3%) women during pregnancy. Compared with women who did not take aspirin, aspirin use was not associated with bleeding complications during the antepartum period (adjusted odds ratio, 1.22; 95% confidence interval, 0.97-1.54). However, aspirin users had a higher incidence of intrapartum bleeding (2.9% aspirin users vs 1.5% nonusers; adjusted odds ratio, 1.63; 95% confidence interval, 1.30-2.05), postpartum hemorrhage (10.2% vs 7.8%; adjusted odds ratio, 1.23; 95% confidence interval, 1.08-1.39), and postpartum hematoma (0.4% vs 0.1%; adjusted odds ratio, 2.21; 95% confidence interval, 1.13-4.34). The risk of a neonatal intracranial hemorrhage was also increased (0.07% vs 0.01%; adjusted odds ratio, 9.66; 95% confidence interval, 1.88-49.48). After stratifying by mode of birth, a higher incidence of bleeding among aspirin users was present for those who had a vaginal birth but not those who had a cesarean delivery.

CONCLUSION

Using aspirin during pregnancy is associated with increased postpartum bleeding and postpartum hematoma. It may also be associated with neonatal intracranial hemorrhage. When offering aspirin during pregnancy, these risks need to be weighed against the potential benefits.