Aspirin use during pregnancy may be a potential risk for postpartum hemorrhage and increased blood loss: a systematic review and meta-analysis

Prophylactic Aspirin Dose and Preeclampsia

Importance

It is unclear whether a higher dose (150-160 mg) or a lower dose (75 mg) of aspirin should be used to prevent preeclampsia.

Objectives

To compare the risk of preeclampsia and bleeding complications between women using 150 to 160 mg of aspirin and those using 75 mg of aspirin for preeclampsia prevention.

Design, Setting, and Participants

This nationwide cohort study included 13 828 women giving birth at 22 weeks' gestation or later in Sweden between January 2017 and December 2020 who used low dose aspirin (75-160 mg) during pregnancy. Data were analyzed from October to November 2023.

Exposure

The use of 150 to 160 mg or 75 mg of aspirin in pregnancy.

Main Outcome and Measures

The main outcome was a preeclampsia diagnosis recorded in the maternal birth record at the time of hospital discharge. The main safety outcome was postpartum hemorrhage, defined as bleeding more than 1000 mL after delivery. Relative risks (RRs) and 95% CIs were estimated using a doubly robust inverse probability-weighted regression adjustment model controlling for background characteristics.

Results

In the total cohort of 13 828 women, the mean (SD) age was 33.0 (5.5) years and 3003 women (21.7%) were nulliparous. Of the women, 4687 (33.9%) were prescribed 150 to 160 mg of aspirin, and 9141 (66.1%) were prescribed 75 mg of aspirin. A total of 10 635 women (76.9%) had at least 2 dispensed prescriptions of low-dose aspirin. Among women using 150 to 160 mg of aspirin, 443 (9.5%) developed preeclampsia compared with 812 (8.9%) of those using 75 mg of aspirin (adjusted RR [aRR], 1.07; 95% CI, 0.93-1.24). Additionally, the risk of postpartum hemorrhage between the groups was similar, with 326 women (6.9%) using 150 to 160 mg of aspirin experiencing a postpartum hemorrhage compared with 581 (6.4%) in the 75-mg group (aRR, 1.08; 95% CI, 0.90-1.30).

Conclusions and Relevance

In this cohort study of 13 828 women, no difference was found in preeclampsia incidence or bleeding complications between those using 150 to 160 mg of aspirin vs 75 mg of aspirin during pregnancy for preeclampsia prevention. These findings suggest that either dose may be a reasonable choice when using aspirin to prevent preeclampsia. However, large randomized trials investigating aspirin dose in pregnancy are still needed.

[Screening and prevention of preeclampsia using the Fetal Medicine Foundation algorithm]

OBJECTIVE

In order to identify women at high risk of pre-eclampsia and offer them aspirin prophylactic treatment, the Fetal Medicine Foundation (FMF) recommends a first-trimester screening test. The commonly used threshold for aspirin administration is a risk >1/100, which implies treating an important number of patients. We aimed to assess the use of this strategy with a more restrictive threshold: risk >1/70 and evaluate the impact of this strategy on the prevalence of pre-eclampsia with premature delivery in nulliparous women.

METHODS

A before-and-after cohort study conducted from 01/09/2014 to 01/12/2018, including nulliparous women undergoing first-trimester ultrasound at the University Hospital of Toulouse. Between 09/2014 and 09/2016 ("before cohort"), women did not undergo pre-eclampsia screening. Between 01/2017 and 12/2018 ("after cohort"), women underwent targeted pre-eclampsia screening using the FMF algorithm, and those with a risk >1/70 received 100mg aspirin. The primary outcome was pre-eclampsia with premature delivery. A univariate and then a multivariate analysis were performed to take into account potential confounding factors.

RESULTS

Among the 1030 women of the before cohort, 17 women (1.7%) experienced pre-eclampsia with premature delivery, compared to 8 women (1.3%) among the 629 of the after cohort, with no significant difference between the two groups (Adjusted Odd Ratio (95%CI)=0.73 [0.31-1.74]). In the after cohort, 18 women (2.9%) had a risk greater than 1/70 and therefore received aspirin. According to the FMF screening test, 89 women (14.1%) had a risk>1/100, which is the usual threshold for prescribing aspirin for prophylaxis. This means that 71 women had a risk greater than 1/100 but less than 1/70 and therefore did not receive aspirin in this study, even though they would have received aspirin at the usual threshold.

CONCLUSIONS

The screening and prevention strategy for pre-eclampsia using restrictive thresholds did not decrease the rate of preeclampsia with premature delivery.

The role of cell-free DNA biomarkers and patient data in the early prediction of preeclampsia: an artificial intelligence model

BACKGROUND

Accurate individualized assessment of preeclampsia risk enables the identification of patients most likely to benefit from initiation of low-dose aspirin at 12 to 16 weeks of gestation when there is evidence for its effectiveness, and enables the guidance of appropriate pregnancy care pathways and surveillance.

OBJECTIVE

The primary objective of this study was to evaluate the performance of artificial neural network models for the prediction of preterm preeclampsia (<37 weeks' gestation) using patient characteristics available at the first antenatal visit and data from prenatal cell-free DNA screening. Secondary outcomes were prediction of early-onset preeclampsia (<34 weeks' gestation) and term preeclampsia (≥37 weeks' gestation).

METHODS

This secondary analysis of a prospective, multicenter, observational prenatal cell-free DNA screening study (SMART) included singleton pregnancies with known pregnancy outcomes. Thirteen patient characteristics that are routinely collected at the first prenatal visit and 2 characteristics of cell-free DNA (total cell-free DNA and fetal fraction) were used to develop predictive models for early-onset (<34 weeks), preterm (<37 weeks), and term (≥37 weeks) preeclampsia. For the models, the "reference" classifier was a shallow logistic regression model. We also explored several feedforward (nonlinear) neural network architectures with ≥1 hidden layers, and compared their performance with the logistic regression model. We selected a simple neural network model built with 1 hidden layer and made up of 15 units.

RESULTS

Of the 17,520 participants included in the final analysis, 72 (0.4%) developed early-onset, 251 (1.4%) preterm, and 420 (2.4%) term preeclampsia. Median gestational age at cell-free DNA measurement was 12.6 weeks, and 2155 (12.3%) had their cell-free DNA measurement at ≥16 weeks' gestation. Preeclampsia was associated with higher total cell-free DNA (median, 362.3 vs 339.0 copies/mL cell-free DNA; P<.001) and lower fetal fraction (median, 7.5% vs 9.4%; P<.001). The expected, cross-validated area under the curve scores for early-onset, preterm, and term preeclampsia were 0.782, 0.801, and 0.712, respectively, for the logistic regression model, and 0.797, 0.800, and 0.713, respectively, for the neural network model. At a screen-positive rate of 15%, sensitivity for preterm preeclampsia was 58.4% (95% confidence interval, 0.569-0.599) for the logistic regression model and 59.3% (95% confidence interval, 0.578-0.608) for the neural network model. The contribution of both total cell-free DNA and fetal fraction to the prediction of term and preterm preeclampsia was negligible. For early-onset preeclampsia, removal of the total cell-free DNA and fetal fraction features from the neural network model was associated with a 6.9% decrease in sensitivity at a 15% screen-positive rate, from 54.9% (95% confidence interval, 52.9-56.9) to 48.0% (95% confidence interval, 45.0-51.0).

CONCLUSION

Routinely available patient characteristics and cell-free DNA markers can be used to predict preeclampsia with performance comparable to that of other patient characteristic models for the prediction of preterm preeclampsia. Logistic regression and neural network models showed similar performance.

Obstetric and perinatal outcomes in women with cerebrovascular accident vs. transient ischemic attack: an evaluation of a population database

PURPOSE

Cerebrovascular accidents (CVAs) and transient ischemic attacks (TIAs) are uncommon neurologic events in women of childbearing age. We aimed to compare pregnancy, delivery, and neonatal outcomes between women who suffered from a CVA and those who experienced a TIA.

METHODS

A retrospective population-based cohort study was performed using the Healthcare Cost and Utilization Project, Nationwide Inpatient Sample. Included were all pregnant women who delivered or had a maternal death in the US between 2004 and 2014. We compared women with an ICD-9 diagnosis of a CVA before or during pregnancy to those diagnosed with a TIA before, during the pregnancy, or during the delivery admission. Pregnancy and perinatal outcomes were compared between the two groups, using multivariate logistic regression to control for confounders.

RESULTS

Among 9,096,788 women in the database, 898 met the inclusion criteria. Of them, 706 women (7.7/100,000) had a CVA diagnosis, and 192 (2.1/100,000) had a TIA diagnosis. Women with a CVA, compared to those with a TIA, had a higher rate of pregnancy-induced hypertension (aOR 3.82,95%CI 2.14-6.81, p < 0.001); preeclampsia (aOR 2.6,95%CI 1.3-5.2, p = 0.007), eclampsia (aOR 13.78,95% CI 1.84-103.41, p < 0.001); postpartum hemorrhage (aOR 4.52,95%CI 1.31-15.56, p = 0.017), blood transfusion (aOR 5.57,95%CI 1.65-18.72, p = 0.006), and maternal death (54 vs. 0 cases, 7.6% vs. 0%), with comparable neonatal outcomes.

CONCLUSION

Women diagnosed with a CVA before or during pregnancy had a higher incidence of myriad maternal complications, including hypertensive disorders of pregnancy, postpartum hemorrhage, and death, compared to women with a TIA diagnosis, with comparable neonatal outcomes, stressing the different prognoses of these two conditions, and the importance of these patients' diligent follow-up and care.

Barriers and facilitators of adherence to low-dose aspirin during pregnancy: A co-produced systematic review and COM-B framework synthesis of qualitative evidence

INTRODUCTION

Women at increased risk of developing pre-eclampsia are advised to take a daily low-dose of aspirin from 12 weeks of pregnancy to reduce their risks. Despite the well-established prophylactic effect of aspirin, adherence to this therapy is low. This systematic review aimed to summarise evidence on the barriers and facilitators of adherence to low-dose aspirin to inform intervention development to support decision making and persistence with aspirin use for pre-eclampsia prevention.

MATERIALS AND METHODS

A systematic review and meta-synthesis of qualitative research was co-produced by representatives from charities, and public, clinical and academic members. Eight electronic databases (MEDLINE, PsycINFO, CINAHL, Web of Science, Scopus, EMBASE, Prospero, OpenGrey), archives of charities and professional organisations were searched (between October and November 2023 and re-run in August 2023) using predefined search terms. Studies containing qualitative components related to barriers and facilitators of adherence to low-dose aspirin during pregnancy were included. Quality assessment was performed using the Critical Appraisal Skills Programme checklist for qualitative research. A combination of the COM-B framework with phases of adherence process as defined by international taxonomy was used as the coding framework. Co-production activities were facilitated by use of 'Zoom' and 'Linoit'.

RESULTS

From a total of 3377 papers identified through our searches, five published studies and one dissertation met our inclusion criteria. Studies were published from 2019 to 2022 covering research conducted in the USA, Canada, UK, Netherlands and Australia. Barriers and facilitators to adherence were mapped to six categories of the COM-B for three phases of adherence: initiation, implementation, and discontinuation. The discontinuation phase of adherence was only mentioned by one author. Four key themes were identified relating to pregnancy: 'Insufficient knowledge', 'Necessity concerns balance', 'Access to medicine', 'Social influences', and 'Lack of Habit'.

CONCLUSIONS

The COM-B framework allowed for detailed mapping of key factors shaping different phases of adherence in behavioural change terms and now provides a solid foundation for the development of a behavioural intervention. Although potential intervention elements could be suggested based on the results of this synthesis, additional co-production work is needed to define elements and plan for the delivery of the future intervention.

TRIAL REGISTRATION

PROSPERO CRD42022359718. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359718.

Aspirin at 75 to 81 mg Daily for the Prevention of Preterm Pre-Eclampsia: Systematic Review and Meta-Analysis

Background: Aspirin at 150 mg daily, initiated in the 1st trimester of pregnancy, prevents preterm pre-eclampsia. We aimed to estimate whether a dose of 75 to 81 mg daily can help to prevent preterm pre-eclampsia as well. Methods: A systematic search was conducted using multiple databases and meta-analyses of randomized controlled trials (RCTs) that compared aspirin initiated in the first trimester of pregnancy to placebo or no treatment, following the PRISMA guidelines and the Cochrane risk of bias tool. Results: We retrieved 11 RCTs involving 13,981 participants. Five RCTs had a low risk of bias, one at unclear risk, and fiver had a high risk of bias. A pooled analysis demonstrated that doses of 75 to 81 mg of aspirin, compared to a placebo or no treatment, was not associated with a significant reduction in preterm pre-eclampsia (8 studies; 12,391 participants; relative risk, 0.66; 95% confidence interval: 0.27 to 1.62; p = 0.36), but there was a significant heterogeneity across the studies (I2 = 61%, p = 0.02). Conclusion: It cannot be concluded that taking 75 to 81 mg of aspirin daily reduces the risk of preterm pre-eclampsia. However, given the significant heterogeneity between the studies, the true effect that such a dose of aspirin would have on pregnancy outcomes could not be properly estimated.

Deciphering the immunological interactions: targeting preeclampsia with Hydroxychloroquine's biological mechanisms

Preeclampsia (PE) is a complex pregnancy-related disorder characterized by hypertension, followed by organ dysfunction and uteroplacental abnormalities. It remains a major cause of maternal and neonatal morbidity and mortality worldwide. Although the pathophysiology of PE has not been fully elucidated, a two-stage model has been proposed. In this model, a poorly perfused placenta releases various factors into the maternal circulation during the first stage, including pro-inflammatory cytokines, anti-angiogenic factors, and damage-associated molecular patterns into the maternal circulation. In the second stage, these factors lead to a systemic vascular dysfunction with consecutive clinical maternal and/or fetal manifestations. Despite advances in feto-maternal management, effective prophylactic and therapeutic options for PE are still lacking. Since termination of pregnancy is the only curative therapy, regardless of gestational age, new treatment/prophylactic options are urgently needed. Hydroxychloroquine (HCQ) is mainly used to treat malaria as well as certain autoimmune conditions such as systemic lupus and rheumatoid arthritis. The exact mechanism of action of HCQ is not fully understood, but several mechanisms of action have been proposed based on its pharmacological properties. Interestingly, many of them might counteract the proposed processes involved in the development of PE. Therefore, based on a literature review, we aimed to investigate the interrelated biological processes of HCQ and PE and to identify potential molecular targets in these processes.

Maternal-neonatal events resulting from medications for preventing hypertensive disorders in high-risk pregnant women: A systematic review and network meta-analysis

BACKGROUND

There have been few studies reporting on maternal and neonatal events in high-risk pregnant women receiving medications for preventing hypertensive disorders of pregnancy (HDP).

OBJECTIVE

To identify placental abruption, postpartum hemorrhage, neonatal intraventricular hemorrhage, and neonates with small for gestational age (SGA) or growth restriction resulting from medications for preventing HDP in high-risk pregnant women using a network meta-analysis.

SEARCH STRATEGY

All randomized controlled trials comparing the most commonly used medications (antiplatelet agents, anticoagulants, antioxidants, nitric oxide, and calcium) for preventing HDP in high-risk pregnant women were searched from the Cochrane Pregnancy and Childbirth's Specialized Register of Controlled Trials until July 31, 2020, without language restriction.

SELECTION CRITERIA

Two of the authors independently selected the eligible trials.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed the methodological quality of the included trials. Pairwise and network meta-analyses were used to determine comparative risk ratios and 95% confidence intervals.

MAIN RESULTS

The 51 included trials involved 69 669 pregnant women. Compared with placebo/no treatment, antioxidants slightly reduced placental abruption with high-certainty evidence. Antiplatelet agents probably reduced SGA with low-certainty evidence and slightly increased neonatal intraventricular hemorrhage with moderate-certainty evidence.

CONCLUSION

Antiplatelet agents probably reduce SGA, but neonatal intraventricular hemorrhage should be monitored.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42018096276.