Prevention of perinatal death and adverse perinatal outcome using low-dose aspirin: a meta-analysis

Evaluation of adjunctive low-dose aspirin after non-prophylactic cerclage on the prevention of spontaneous preterm birth in singleton pregnancy: a nonrandomized controlled trial

BACKGROUND

Cervical cerclage cannot guarantee a full-term delivery. Recently, several studies have suggested that low-dose aspirin taken in pregnancy may reduce the likelihood of spontaneous preterm birth (sPTB). Our study aimed to evaluate whether adjunctive low-dose aspirin after non-prophylactic cerclage would reduce the rate of sPTB and improve pregnancy outcomes.

METHODS

A prospective clinical trial was conducted between September 2020 and July 2023 at two Tertiary A hospitals in Zhejiang Province, China. Singleton pregnancies with asymptomatic cervical dilation or cervical shortening and arranged non- prophylactic cerclage at 16-26 gestational weeks were included. Eligible women were assigned into either aspirin + regular therapy (Aspirin group) or only regular therapy group (No-aspirin group) based on their discretion. Propensity score matching was used to control confounding. The primary outcome was the incidence of sPTB at < 28 weeks of gestation.

RESULTS

A total of 230 women underwent cervical cerclage with extra aspirin therapy (n = 83) or regular therapy (n = 147) were identified. Overall, all participants were 1:1 propensity score-matched with 75 in Aspirin group and 75 in No-aspirin group. The rates of sPTB at < 28 and < 32 weeks were significantly lower in Aspirin group than in No-aspirin group. A greater proportion of pregnancies were prolonged at least 28 days and 56 days among women received additional aspirin than regular therapy. The overall perinatal mortality was significantly lower in Aspirin group (2.67%) than in No-aspirin group (17.33%) (p < 0.01). In ultrasound-indicated cerclage, the incidence of sPTB at < 32 weeks was significantly lower in Aspirin group, whereas in physical- indicated cerclage, it did not reach a significate difference.

CONCLUSION

We indicated that the administration of low-dose aspirin in singleton pregnancies after non-prophylactic cerclage was associated with a significant decrease in extremely preterm birth.

TRIAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry with a registration number of ChiCTR2000034662 at 2020-07-13 ( https://www.chictr.org.cn/ ).

Cost-effectiveness of a randomized controlled trial comparing low-dose aspirin to placebo for the prevention of recurrent preterm birth

To assess the cost-effectiveness of low-dose aspirin compared to placebo for the prevention of recurrent preterm birth from a healthcare perspective. This was a cost-effectiveness analysis alongside a multicenter, randomized, double-blinded, placebo-controlled trial. We included women with a singleton pregnancy and a previous spontaneous preterm birth <37 weeks of gestation of a singleton. Women were randomized between aspirin 80 mg daily and placebo, initiated between 8 and 16 weeks of gestation. We estimated the difference in preterm births (<37 weeks of gestation), and maternal and neonatal healthcare costs using seemingly unrelated linear regression analyses. Bootstrapping was performed to estimate statistical uncertainty. A total of 387 women were included: 194 in the aspirin group and 193 in the placebo group. We observed a small, statistically non-significant difference in preterm birth (21.2% vs. 25.4%; risk difference -4.3%; 95% CI: -12.7% to 4.1%) and healthcare costs (mean -€99; 95% CI: -€2385 to €2325) in the aspirin group compared to placebo. The cost-effectiveness acceptability curve showed that the probability of aspirin being cost-effective was 54% for a willingness to pay threshold of €0 for one prevented preterm birth and 78% for €50 000 for one prevented preterm birth. Our findings suggest that aspirin is the dominant strategy over placebo for the prevention of preterm birth. However, there was substantial uncertainty around the results and definite conclusions regarding the cost-effectiveness of aspirin cannot be drawn.

Optimal Aspirin Dosage for the Prevention of Preeclampsia and Other Adverse Pregnancy Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Objectives: This systematic review and meta-analysis aimed to determine the effectiveness of different aspirin dosages in preventing preeclampsia and its effect on other pregnancy-associated conditions. Methods: A comprehensive search of three databases (Pubmed, Embase, and Cochrane Library) was conducted for randomized controlled trials without time interval criteria, comparing aspirin at various doses with placebo or no specific preeclampsia prophylaxis. Eligible randomized controlled trials (RCTs) examined pregnant women receiving aspirin at any dose and time during their pregnancy, while the control group received a placebo, or placebo and a different dose of aspirin, or no specific preeclampsia prevention. No exclusion criteria were established regarding the population, study size, study site, or length of aspirin prophylaxis. Studies examining additional preventive medication (such as low-molecular-weight heparin) compared to aspirin without a placebo group were excluded. For all outcomes, the risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Meta-regression was performed to examine the relation between aspirin dosage and preeclampsia. Results: Based on the analysis of 31 studies involving 28,318 pregnancies and 20 studies involving 26,551 pregnancies, the early initiation of aspirin significantly reduced the overall incidence of preeclampsia (RR = 0.63, CI: 0.47-0.84) and perinatal death risk (RR = 0.82, CI: 0.72-0.93), respectively. Based on our meta-regression model, we could not establish a dose-dependent correlation between aspirin dosage and the risk of preeclampsia. Conclusions: Early-initiated aspirin prophylaxis is effective in preventing preeclampsia, without raising the incidence of placental abruption or increasing the amount of peripartum bleeding. No specific dose was superior to others; thus, further research should explore higher doses and focus on preterm preeclampsia, maternal-fetal complications, and bleeding.

Maternal and fetal outcomes of autoimmune hepatitis in pregnancy: A United States hospitalized patient study

BACKGROUND

Autoimmune hepatitis (AIH) is a chronic inflammatory disease primarily affecting the liver, with a higher prevalence among women of reproductive age. The latest nationwide statistics regarding its impact on maternal and fetal outcomes during pregnancy are lacking.

AIMS

To analyze the real impact of AIH on maternal and fetal outcomes in hospitalized delivery patients, and provide theoretical guidance for comprehensive clinical management.

METHODS

A retrospective analysis was conducted using data from the 2016-2020 National Inpatient Sample database in the United States. Multivariate logistic regression analysis was used to assess the influence of AIH on maternal and fetal outcomes during pregnancy.

RESULTS

A total of 17,825,445 hospitalized delivery patients were included, among which 1,185 had AIH. After adjusting for potential confounding factors, compared to hospitalized delivery patients without AIH, the AIH group exhibited significantly higher rates of adverse maternal and fetal outcomes, including hypertension complications of pregnancy (AOR 1.68, 95 % CI 1.09-2.58), preterm birth (AOR 2.89, 95 % CI 1.91-4.38), fetal growth restriction (AOR 2.21, 95 % CI 1.34-3.64), and fetal death (AOR 4.13, 95 % CI 1.33-12.83). AIH showed no association with cesarean section or large fetus. In the group of delivery in patients with AIH, patients who develop hypertensive disorders have a higher probability of concomitant diabetes mellitus (OR 6.85, 95 % CI 2.19-21.45), hypertension (OR 4.64, 95 % CI 1.68-12.82), and obesity (OR 3.06, 95 % CI 1.26-7.42). Additionally, AIH patients incurred higher total costs and longer hospital stays during the delivery hospitalization.

CONCLUSION

Patients with AIH face an increased risk of hypertensive disorders of pregnancy, preterm birth, fetal growth restriction, and fetal death during delivery. It is crucial to enhance awareness of these potential occurrence risks.

Aspirin dosage for preeclampsia prophylaxis: an argument for 81-mg dosing

Research conducted over the past few decades has shown that low-dose aspirin can effectively reduce the risk of developing preeclampsia. Consequently, numerous prominent organizations have adopted the recommendation to use low-dose aspirin during pregnancy to prevent preeclampsia. However, the optimal dosage of low-dose aspirin (81mg versus 162mg) remains a subject of debate. Currently, there is insufficient high-quality data to justify the use of a higher dosage of low-dose aspirin. In this review, we review the existing evidence that supports the continued use of 81mg of aspirin over a higher dose and emphasize the need for high-quality research to alter current recommendations.

Aspirin dosage for preeclampsia prophylaxis: an argument for 162-mg dosing

The optimal aspirin dose for preeclampsia prevention remains controversial, with international guidelines lacking consensus on the most effective regimen. Aspirin is a proven intervention for reducing the risk of preeclampsia, particularly when initiated early in pregnancy. Its benefits stem from the selective inhibition of cyclooxygenase-1 (COX-1), reducing thromboxane A2 synthesis while preserving prostacyclin production, thereby restoring the vascular balance essential for placental health. A dose-response relationship has been established, with doses ≥100 mg showing significantly greater efficacy than lower doses. Furthermore, aspirin's pharmacological effects remain highly specific to COX-1 at the 162 mg dose, minimizing concerns about broader prostaglandin inhibition. Emerging evidence suggests that certain patient factors, such as altered pharmacokinetics during pregnancy or obesity, may reduce aspirin's effectiveness at lower doses (e.g., 81 mg). In these studies, aspirin resistance was successfully overcome with a 162 mg dose. While concerns regarding safety at this dose have been raised, contemporary randomized controlled trials utilizing a 150 mg dose have shown no increase in adverse effects compared to placebo. As such, current evidence increasingly supports 162 mg as the optimal dose for preeclampsia prevention, offering greater effectiveness than the commonly used 81 mg dose, without significant evidence of increased risk.

Intracranial Hemorrhage During Pregnancy: An Interdisciplinary Literature Review and a Rare Case Report of Early-Onset Eclampsia with Intracranial Hemorrhage and HELLP Syndrome

Intracranial hemorrhage is a rare yet potentially devastating event during pregnancy with a significant risk of maternal and fetal mortality and morbidity. The risk of intracranial hemorrhage increases during the third trimester of pregnancy and is greatest during labor and the postpartum period. Interdisciplinary diagnosis and treatment of the pregnant population often begins in the emergency department setting and is key to increasing patient survival rates through immediate and adequate treatment, including emergency medicine, neurosurgical and obstetrical procedures. A unique case report with a diagnostic pathway for intracranial hemorrhage due to eclampsia in a primipara at 24 weeks of gestation is presented, illustrating potential diagnostic dilemmas as the patient rapidly progresses into hemolysis, elevated liver enzymes and low platelets syndrome. A literature review was conducted to uncover the etiology of intracranial hemorrhage during pregnancy, as well as its diagnostic challenges and treatment. Pregnancy should not be viewed as a barrier to performing angiography or endovascular treatment for vascular causes of intracranial hemorrhage. Patient transport to a tertiary reference center and the interdisciplinary cooperation of specialists are key to achieving correct and rapid treatment. Continuous prevention of preeclampsia and patient education are necessary to decrease the incidence of eclampsia and its complications. Key message: Intracranial hemorrhage and eclampsia in pregnant patients are rare yet may result in high rates of maternal and fetal morbidity and mortality. The diagnostic process is difficult and requires interdisciplinary cooperation to start the correct treatment immediately.

First-Trimester PlGF and PAPP-A and the Risk of Placenta-Mediated Complications: PREDICTION Prospective Study

OBJECTIVES

This study aimed to estimate the association between low first-trimester maternal serum PlGF (placental growth factor) and PAPP-A (pregnancy-associated plasma protein A) and the risk of placenta-mediated complications.

METHODS

We performed a secondary analysis of the PREDICTION study, including nulliparous participants recruited at 11 to 14 weeks of pregnancy. First-trimester PlGF and PAPP-A levels were reported in multiples of the median (MoM) adjusted for maternal characteristics and gestational age. Participants were stratified into 4 groups based on absence/presence of low (<0.4 MoM) PlGF and PAPP-A values. A composite of adverse pregnancy outcomes (including preeclampsia, fetal growth restriction, fetal death, and placental abruption) was calculated for deliveries occurring before 34 weeks, before 37 weeks, and at or after 37 weeks.

RESULTS

Out of the 7262 participants, 86 (1.2%) experienced the composite outcome before 37 weeks of gestation, including 35 (0.4%) before 34 weeks. The combination of low PAPP-A and low PlGF levels was associated with the greatest risk of adverse outcomes before 37 weeks (21%) and before 34 weeks (12%) compared with low PlGF alone (7% and 3%), low PAPP-A alone (2% and 1%), or neither marker (1% and 0.4%, respectively; P < 0.001). For preterm preeclampsia specifically, the combination of low PAPP-A and low PlGF was also associated with a greater risk (12%) compared with low PlGF alone (6%), low PAPP-A alone (0.5%), or neither marker (0.7%; P < 0.001).

CONCLUSIONS

The combination of low PAPP-A and low PlGF levels is associated with a very high risk for adverse outcomes before 34 and 37 weeks. An isolated low PAPP-A should not be considered a risk factor for adverse pregnancy outcomes.

Combined first-trimester screening for preterm small-for-gestational-age infants: Australian multicenter clinical feasibility study

OBJECTIVE

To assess the performance of the Fetal Medicine Foundation (FMF) first-trimester competing-risks screening model for small-for-gestational-age (SGA) fetuses requiring delivery at < 37 weeks' gestation, in a large cohort of women receiving maternity care in Australia.

METHODS

This was a retrospective analysis of prospectively collected data from a cohort of women attending one of two private multicenter fetal medicine practices for first-trimester screening for preterm pre-eclampsia (PE), defined as PE requiring delivery before 37 weeks' gestation. Risk for preterm SGA, defined as SGA requiring delivery before 37 weeks, was calculated but was not disclosed to the patient or referring physician. Screening data were matched to obstetric outcomes. The primary outcome was the efficacy of the FMF screening model in assessing the risk of preterm SGA. The potential effect on identifying other adverse pregnancy outcomes was also assessed.

RESULTS

During the study period, 22 841 women with a singleton pregnancy underwent combined first-trimester screening for preterm PE. These data were compared with those of 301 721 women in the state of Victoria with a singleton pregnancy who did not undergo screening during the study period. Calculation of the risk for preterm SGA identified 3030 (13.3%) pregnancies as high risk. The sensitivity of the model was 48.6% (95% CI, 41.0-56.2%), specificity was 87.0% (95% CI, 86.6-87.5%) and positive and negative predictive values were 2.9% (95% CI, 2.7-3.1%) and 99.5% (95% CI, 99.4-99.6%), respectively. Pregnancies at high risk for preterm SGA were also more likely to have preterm PE (risk ratio (RR), 2.28 (95% CI, 1.72-3.03)) and preterm birth (RR, 1.46 (95% CI, 1.32-1.63)), compared with unscreened pregnancies. Pregnancies at low risk for preterm SGA were less likely to result in a stillbirth (RR, 0.64 (95% CI, 0.47-0.86)) compared with unscreened pregnancies.

CONCLUSION

Combined first-trimester screening for preterm SGA shows moderate screening efficacy and therefore could help to inform pregnancy management and improve antenatal resource allocation. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Efficacy of combining aspirin with hydroxychloroquine in pregnancies at high risk for pre-eclampsia: a prospective, multicentre, open-label, single-arm clinical trial, investigator-initiated study (HUGS study)

INTRODUCTION

The use of hydroxychloroquine (HCQ) during pregnancies complicated by systemic lupus erythematosus or refractory antiphospholipid antibody syndrome has demonstrated a significant ability to prevent pre-eclampsia (PE). As such, the potential for the administration of HCQ to prevent PE in other high-risk pregnancies is an important clinical research agenda among maternal and fetal medicine specialists. Mechanistically, the anti-inflammatory and immunomodulatory effects of HCQ can offer vascular protection and inhibit the placental dysfunction-associated thrombotic changes underlying the pathophysiology of PE, fetal growth restriction (FGR) and fetal death in utero (FDIU). Placenta-mediated complications exhibit a distinctive overlapping syndrome between pregnancies, and low-dose aspirin is the only prevention method currently in use. This study investigated the effects of improvements in outcomes with HCQ administration in high-risk pregnancies complicated by a previous experience of PE, FGR or FDIU.

METHODS AND ANALYSIS

This multicentre, open-label, single-arm trial commenced on 31 May 2022, in three tertiary hospitals in Korea. Pregnant women with a prior history of PE, FGR or FDIU are eligible to participate. This single-arm study set the previous study with the most similar inclusion criteria, aspirin dose and drug administration period as the comparison group. The required sample size was determined to be 58, with an expected dropout rate of 10%.

ETHICS AND DISSEMINATION

This study protocol was approved by the following institutions and committees: Institutional Review Boards of Chung-Ang University Gwangmyeong Hospital (2304-082-056), Samsung Medical Center (2021-11-087-003) and Kyungpook National University Chilgok Hospital (2021-06-005-006) and the Ministry of Food and Drug Safety. The results will be disseminated to the general public, grant funder, maternal-fetal medicine specialists and other researchers.

TRIAL REGISTRATION NUMBER

NCT05287321.

Impact of low-dose aspirin exposure on obstetrical outcomes: a meta-analysis

OBJECTIVE

To assess the impact of low-dose aspirin (LDA) on obstetrical outcomes through a meta-analysis of placebo-controlled randomized controlled trials (RCTs).

METHODS

A systematic search of the PubMed, Cochrane Library, Web of Science and Embase databases from inception to January 2024 was conducted to identify studies exploring the role of aspirin on pregnancy, reporting obstetrical-related outcomes, including preterm birth (PTB, gestational age <37 weeks), small for gestational age (SGA), low birth weight (LBW, birthweight < 2500g), perinatal death (PND), admission to the neonatal intensive care unit (NICU), 5-min Apgar score < 7 and placental abruption. Relative risks (RRs) were estimated for the combined outcomes. Subgroup analyses were performed by risk for preeclampsia (PE), LDA dosage (<100 mg vs. ≥100 mg) and timing of onset (≤20 weeks vs. >20 weeks).

RESULTS

Forty-seven studies involving 59,124 participants were included. Compared with placebo, LDA had a more significant effect on low-risk events such as SGA, PTB and LBW. Specifically, LDA significantly reduced the risk of SGA (RR = 0.91, 95% CI: 0.87-0.95), PTB (RR = 0.93, 95% CI: 0.89-0.97) and LBW (RR = 0.94, 95% CI: 0.89-0.99). For high-risk events, LDA significantly lowered the risk of NICU admission (RR = 0.93, 95% CI: 0.87-0.99). On the other hand, LDA can significantly increase the risk of placental abruption (RR = 1.72, 95% CI: 1.23-2.43). Subgroup analyses showed that LDA significantly reduced the risk of SGA (RR = 0.86, 95% CI: 0.77-0.97), PTB (RR = 0.93, 95% CI: 0.88-0.98) and PND (RR = 0.65, 95% CI: 0.48-0.88) in pregnant women at high risk of PE, whereas in healthy pregnant women LDA did not significantly improve obstetrical outcomes, but instead significantly increased the risk of placental abruption (RR = 5.56, 95% CI: 1.92-16.11). In pregnant women at high risk of PE, LDA administered at doses ≥100 mg significantly reduced the risk of SGA (RR = 0.77, 95% CI: 0.66-0.91) and PTB (RR = 0.56, 95% CI: 0.32-0.97), but did not have a statistically significant effect on reducing the risk of NICU, PND and LBW. LDA started at ≤20 weeks significantly reduced the risk of SGA (RR = 0.76, 95% CI: 0.65-0.89) and PTB (RR = 0.56, 95% CI: 0.32-0.97).

CONCLUSIONS

To sum up, LDA significantly improved neonatal outcomes in pregnant women at high risk of PE without elevating the risk of placental abruption. These findings support LDA's clinical application in pregnant women, although further research is needed to refine dosage and timing recommendations.

Sensitive objective markers for measuring aspirin responsiveness in pregnancy: An explorative scoping review

BACKGROUND

Aspirin is frequently used in pregnancy to decrease the risk of developing pre-eclampsia. Studies have highlighted this potential benefit which in theory happens by inhibition of platelet function. However, questions remain on the appropriate dosing and the reliability of serum markers in determining aspirin responsiveness in pregnancy (ARP).

OBJECTIVE

review the literature on ARP and identify the gaps, followed by investigating the objective biomarkers used to assess ARP. This includes the factors associated such as aspirin formulations, doses, and patient comorbidities.

METHODS

A comprehensive search was conducted using keywords such as 'aspirin', 'pregnancy', and 'responsiveness' in relevant databases such as PubMed, SCOPUS, Cochrane from inception to March 2024. Our inclusion criteria enrolled pregnant women aged 18 years old and above, irrespective of their trimester status, who were prescribed aspirin for any medical indication.

RESULTS

The research findings encompass three key areas. Firstly, examination of the impact of different aspirin formulations on responsiveness revealed no significant differences between different formulations. Secondly, nine papers were identified with varied dosages of administered aspirin, highlighting a need for standardized approach to dosing, and investigating higher dosing and its impact. Thirdly, there is a lack of consensus on biomarkers used to assess ARP. Finally, this synthesis sheds light on prognostic factors of developing aspirin non-responsiveness, such as medical comorbidities.

CONCLUSION

This scoping review identifies several residual uncertainties on ARP. The main gaps are validation of serum markers, understanding the influence of underlying morbidity on ARP, and determining appropriate aspirin dosing in pregnancy.

Aspirin dose for preeclampsia prophylaxis: an argument for 162-mg dosing

The optimal aspirin dose for preeclampsia prevention remains controversial, with international guidelines lacking consensus on the most effective regimen. Aspirin is a proven intervention for reducing the risk of preeclampsia, particularly when initiated early in pregnancy. Its benefits stem from the selective inhibition of cyclooxygenase-1 (COX-1), reducing thromboxane A2 synthesis while preserving prostacyclin production, thereby restoring the vascular balance essential for placental health. A dose-response relationship has been established, with doses ≥100 mg showing significantly greater efficacy than lower doses. Furthermore, aspirin's pharmacological effects remain highly specific to COX-1 at the 162 mg dose, minimizing concerns about broader prostaglandin inhibition. Emerging evidence suggests that certain patient factors, such as altered pharmacokinetics during pregnancy or obesity, may reduce aspirin's effectiveness at lower doses (e.g., 81 mg). In these studies, aspirin resistance was successfully overcome with a 162 mg dose. While concerns regarding safety at this dose have been raised, contemporary randomized controlled trials utilizing a 150 mg dose have shown no increase in adverse effects compared to placebo. As such, current evidence increasingly supports 162 mg as the optimal dose for preeclampsia prevention, offering greater effectiveness than the commonly used 81 mg dose, without significant evidence of increased risk.

Early pregnancy maternal blood pressure and risk of preeclampsia: Does the association differ by parity? Evidence from 14,086 women across 7 countries

OBJECTIVE

To determine if the relationship between blood pressure (BP) before 16 weeks' gestation and subsequent onset of preeclampsia differs by parity, and by history of hypertensive disorders of pregnancy (HDP) in parous women.

STUDY DESIGN

Data from two studies were pooled. First, routinely collected clinical data from three metropolitan hospitals in Sydney, Australia (2017-2020), where BP was measured as part of routine clinical care using validated mercury-free sphygmomanometers. Second, prospectively collected research data from the INTERBIO-21st Study, conducted in six countries, investigating the epidemiology of fetal growth restriction and preterm birth, where BP was measured by dedicated research staff using an automated machine validated for use in pregnancy.

MAIN OUTCOME

Adjusted odds ratios (aOR) (95% confidence interval (CI)) for the association of systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) with preeclampsia were obtained from logistic regression models. Models were adjusted for age, smoking, body mass index, previous hypertension, previous diabetes, and previous preeclampsia. Interactions for parity, and history of HDP in parous women were included.

RESULTS

There were 14,086 pregnancies (Sydney = 11008, INTERBIO-21st = 3078) in the pooled analyses, 6914 (49 %) were parous, of which 414 (6.0 %) had a history of HDP. Nulliparous women had a higher risk of preeclampsia (2.6 %) compared with parous women (1.5 %): [aOR (95 %CI) 3.61 (2.67, 4.94)], as did parous women with a history of HDP (15.0 %) compared with no history (0.7 %) [12.70 (8.02, 20.16)]. MAP before 16 weeks' gestation (mean [SD] 78.8[8.6] mmHg) was more strongly associated than SBP or DBP with development of preeclampsia in parous women [2.22 (1.81, 2.74)] per SD higher MAP] compared with nulliparous women [1.58 (1.34, 1.87)] (p for interaction 0.013). There were no significant differences on the effect of blood pressure on preeclampsia in parous women by history of HDP (p for interaction 0.5465).

CONCLUSION

The risk of preeclampsia differs according to parity and history of HDP in a previous pregnancy. Blood pressure in early pregnancy predicts preeclampsia in all groups, although more strongly associated in parous than nulliparous women, but no different in parous women by history of HDP.

Impact of a Stage-Based Classification on the Incidence of Fetal Growth Restriction, Preterm Birth Rates, and Birthweight in a Rural Community of Central India

INTRODUCTION

The objective of this study was to determine the impact of the stage-based classification of fetal growth restriction (FGR) on the magnitude of FGR, preterm births (PTBs), and birthweight (BW) in a rural population of Madhya Pradesh in Central India.

METHODS

The program covered 168 public sector centers for pregnant women and infants that provided services to nearly 220,000 people. The third-trimester assessments included fetal biometry, growth and environment assessments, and Doppler assessments. Fetal growth was staged using the Barcelona protocol as stages 1-4 FGR, small for gestational age, and no FGR. The data from the last ultrasound assessment before childbirth were considered. Regular training programs covering preconception care, antenatal and postnatal care were organized in the local language for the public sector community health workers of the program district. Childbirth outcomes were collected from the obstetric service of the local public sector hospital.

RESULTS

The analysis included 1,229 pregnancies from 2019 to 2023. The overall magnitude of FGR using estimated fetal weight <10th centile was 19.61% and reduced to 13.34% with the stage-based classification. The magnitude of FGR using the stage-based classification reduced from 27.59% in 2019 to 8.95% in 2023. The PTB in the stage-based FGR subgroup declined from 35.0% in 2019 to 3.45% in 2023 and 96.55% of the stage 1 FGR babies in 2023 were delivered at term. The overall mean BW in the program area improved from 2,772.41 (357.11) g in 2019 to 2,819.68 (377.31) g in 2023. The perinatal mortality rate (8.95 per 1,000 pregnancies) in the program area for 2019-2023 was much lower than the 31.9 per 1,000 pregnancies reported for Madhya Pradesh.

CONCLUSION

The change to a stage-based classification of FGR integrated with low-dose aspirin and fetal Doppler studies reduced the incidence of FGR and PTB and perinatal mortality and increased BW in this rural community.

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.

The effects of low-dose aspirin on preterm birth: a systematic review and meta-analysis of randomized controlled trials

AIM

To conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) that evaluated the efficacy of low-dose aspirin (LDA, ≤ 160 mg/day) on preventing preterm birth (PB).

METHODS

Five databases were screened from inception until June 25, 2023. The RCTs were assessed for quality according to Cochrane's risk of bias tool. The endpoints were summarized as risk ratio (RR) with 95% confidence interval (CI).

RESULTS

Overall, 40 RCTs were analyzed. LDA significantly decreased the risk of PB < 37 weeks (RR: 0.91, 95% CI 0.87, 0.96, p < 0.001, moderate certainty of evidence) with low between-study heterogeneity (I2 = 23.2%, p = 0.11), and PB < 34 weeks (RR: 0.78, 95% CI 0.61, 0.99, p = 0.04, low certainty of evidence) with high between-study heterogeneity (I2 = 58.3%, p = 0.01). There were no significant differences between both groups regarding the risk of spontaneous (RR: 0.94, 95% CI 0.83, 1.07, p = 0.37) and medically indicated (RR: 1.28, 95% CI 0.87, 1.88, p = 0.21) BP < 37 weeks. Sensitivity analysis revealed robustness for all outcomes, except for the risk of PB < 34 weeks. For PB < 37 weeks and PB < 34 weeks, publication bias was detected based on visual inspection of funnel plots for asymmetry and statistical significance for Egger's test (p = 0.009 and p = 0.0012, respectively).

CONCLUSION

LDA can significantly reduce the risk of PB < 37 and < 34 weeks. Nevertheless, further high-quality RCTs conducted in diverse populations, while accounting for potential confounding factors, are imperative to elucidate the optimal aspirin dosage, timing of initiation, and treatment duration for preventing preterm birth and to arrive at definitive conclusions.

First-trimester preterm preeclampsia prediction model for prevention with low-dose aspirin

INTRODUCTION

Preeclampsia (PE) is a major maternal and fetal threat. Previous risk-scoring methods in guidelines lacked precision. The Fetal Medicine Foundation (FMF) proposed a first-trimester PE screening model using Bayes' theorem.

PE PREDICTION MODEL

FMF prediction model combines maternal characteristics and medical/obstetrical history to determine prior risk and further incorporate maternal blood pressure, maternal serum biomarkers, and uterine Doppler pulsatility index expressed as multiples of the median (MoM) to estimate posterior risk.

LOW-DOSE ASPIRIN PREVENTION

Low-dose aspirin is one of the potential PE prevention strategies. Initiating it before 16 weeks is crucial. Aspirin's antiplatelet and anti-inflammatory properties align with PE's pathophysiology. Dosing and resistance warrant further study, but a standard regimen of 150 mg nightly, starting before 16 weeks, is widely supported.

PE PREVENTION IN PRACTICE

Clinical trials, including ASPRE, affirm aspirin's role in PE prevention. Starting aspirin based on FMF screening significantly reduces preterm PE and associated complications.

ADVANCEMENTS AND PROSPECTS

Emerging research explores predictors like maternal ophthalmic arterial waveform. Regional variations, especially in Asian populations, are considered. Machine learning and AI show promise, but examiner expertise remains essential for accurate prediction. In conclusion, integrating FMF's first-trimester PE screening with low-dose aspirin offers a promising strategy. Further advancements may enhance precision and broaden prevention efforts.

Hydroxychloroquine in obstetrics: potential implications of the prophylactic use of hydroxychloroquine for placental insufficiency during pregnancy

Proper placentation during early pregnancy is a key factor for maintaining a healthy pregnancy. Placental insufficiency leads to critical complications such as preeclampsia, fetal growth restriction, and fetal demise. These complications are often associated with pathological findings of restricted remodeling and obstructive lesions of the myometrial spiral arteries, which have high recurrence rates during subsequent pregnancies. Currently, there are no pharmacological interventions other than aspirin for the prevention of preeclampsia. Hydroxychloroquine (HCQ), a well-known antimalarial drug, reduces inflammatory and thrombotic changes in vessels. For decades, the use of HCQ for autoimmune diseases has resulted in the successful prevention of both arterial and venous thrombotic events and has been extended to the treatment of lupus and antiphospholipid antibody syndrome during pregnancy. HCQ reduces the risk of preeclampsia with lupus by up to 90%. Several recent studies have investigated whether HCQ improves pregnancy outcomes in women with a history of poor outcomes. In addition, in vitro and animal studies have demonstrated the beneficial effects of HCQ in improving endothelial dysfunction and alleviating hypertension and proteinuria. Therefore, we hypothesized that HCQ has the potential to attenuate the vascular inflammatory and thrombogenic pathways associated with placental insufficiency and conducted a multicenter clinical trial on the efficacy of combining aspirin with HCQ for pregnancies at high risk for preeclampsia in Korea. This study summarizes the potential effects of HCQ on pregnancies with placental insufficiency and the implications of HCQ treatment in the field of obstetrics.

Prevention of preeclampsia

Preeclampsia is a relatively common pregnancy complication and constitutes a major cause of morbidity and mortality for mothers and children worldwide. It disproportionally affects low-resource countries. Appropriate identification of individuals at increased risk and prevention of the disease and its complications remain healthcare and research priorities, and the investigation of potential interventions to prevent preeclampsia has driven much of the obstetric research in recent decades. In this article, we review the scientific literature on the topic, highlighting established benefits and remaining questions regarding different non-pharmacological and pharmacological strategies, including exercise, the timing of birth, aspirin and calcium use, among others, as well as potential novel therapies under investigation.

[Preeclampsia: Guidelines for clinical practice from the French College of Obstetricians and Gynecologists]

OBJECTIVE

To identify strategies to reduce maternal and neonatal morbidity related to preeclampsia.

MATERIAL AND METHODS

The quality of evidence of the literature was assessed following the GRADE® method with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on PubMed, Cochrane, EMBASE and Google Scholar databases. The quality of the evidence was assessed (high, moderate, low, very low) and recommendations were formulated as a (i) strong, (ii) weak or (iii) no recommendation. The recommendations were reviewed in two rounds with external reviewers (Delphi survey) to select the consensus recommendations.

RESULTS

Preeclampsia is defined by the association of gestational hypertension (systolic blood pressure≥140mmHg and/or diastolic blood pressure≥90mmHg) and proteinuria≥0.3g/24h or a Proteinuria/Creatininuria ratio≥30mg/mmol occurring after 20 weeks of gestation. Data from the literature do not show any benefit in terms of maternal or perinatal health from implementing a broader definition of preeclampsia. Of the 31 questions, there was agreement between the working group and the external reviewers on 31 (100%). In general population, physical activity during pregnancy should be encouraged to reduce the risk of preeclampsia (Strong recommendation, Quality of the evidence low) but an early screening based on algorithms (Weak recommendation, Quality of the evidence low) or aspirin administration (Weak recommendation, Quality of the evidence very low) is not recommended to reduce maternal and neonatal morbidity related to preeclampsia. In women with preexisting diabetes or hypertension or renal disease, or multiple pregnancy, the level of evidence is insufficient to determine whether aspirin administration during pregnancy is useful to reduce maternal and perinatal morbidity (No recommendation, Quality of the evidence low). In women with a history of vasculo-placental disease, low dose of aspirin (Strong recommendation, Quality of the evidence moderate) at a dosage of 100-160mg per day (Weak recommendation, Quality of the evidence low), ideally before 16 weeks of gestation and not after 20 weeks of gestation (Strong recommendation, Quality of the evidence low) until 36 weeks of gestation (Weak recommendation, Quality of the evidence very low) is recommended. In a high-risk population, additional administration of low molecular weight heparin is not recommended (Weak recommendation, Quality of the evidence moderate). In case of preeclampsia (Weak recommendation, Quality of the evidence low) or suspicion of preeclampsia (Weak recommendation, Quality of the evidence moderate, the assessment of PlGF concentration or sFLT-1/PlGF ratio is not routinely recommended) in the only goal to reduce maternal or perinatal morbidity. In women with non-severe preeclampsia antihypertensive agent should be administered orally when the systolic blood pressure is measured between 140 and 159mmHg or diastolic blood pressure is measured between 90 and 109mmHg (Weak recommendation, Quality of the evidence low). In women with non-severe preeclampsia, delivery between 34 and 36+6 weeks of gestation reduces severe maternal hypertension but increases the incidence of moderate prematurity. Taking into account the benefit/risk balance for the mother and the child, it is recommended not to systematically induce birth in women with non-severe preeclampsia between 34 and 36+6 weeks of gestation (Strong recommendation, Quality of evidence high). In women with non-severe preeclampsia diagnosed between 37+0 and 41 weeks of gestation, it is recommended to induce birth to reduce maternal morbidity (Strong recommendation, Low quality of evidence), and to perform a trial of labor in the absence of contraindication (Strong recommendation, Very low quality of evidence). In women with a history of preeclampsia, screening maternal thrombophilia is not recommended (Strong recommendation, Quality of the evidence moderate). Because women with a history of a preeclampsia have an increased lifelong risk of chronic hypertension and cardiovascular complications, they should be informed of the need for medical follow-up to monitor blood pressure and to manage other possible cardiovascular risk factors (Strong recommendation, Quality of the evidence moderate).

CONCLUSION

The purpose of these recommendations was to reassess the definition of preeclampsia, and to determine the strategies to reduce maternal and perinatal morbidity related to preeclampsia, during pregnancy but also after childbirth. They aim to help health professionals in their daily clinical practice to inform or care for patients who have had or have preeclampsia. Synthetic information documents are also offered for professionals and patients.

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.

Cost-effectiveness analysis of a first-trimester screening test for preterm preeclampsia in the Netherlands

OBJECTIVES

The risk of preterm preeclampsia (PT PE) can significantly be reduced by starting acetylsalicylic acid ≤ 16 weeks of gestational age. First trimester predictive models based on maternal risk factors to effectively start this therapy lacked sufficient power, but recent studies showed that these models can be improved by including test results of biochemical and/or -physical markers. To investigate whether testing a biochemical marker in the first trimester is cost-effective in the Netherlands, a cost-effectiveness analysis was performed in this study.

STUDY DESIGN

The outcome of this study was expressed as an incremental cost-effectiveness ratio (ICER) with as effect prevented PT PE cases. To evaluate the impact of each model parameter and to determine model uncertainties, both univariate and probabilistic sensitivity analyses were performed.

RESULTS

When compared to the baseline strategy, the test strategy is estimated to save almost 4 million euros per year on a national scale and at the same time this would prevent an additional 228 PT PE cases. The sensitivity analyses showed that the major drivers of the result are the costs to monitor a high-risk pregnancy and the specificity and that most of the model simulations were in the southeast quadrant: cost saving and more prevented complications.

CONCLUSIONS

This study showed that a first-trimester test strategy to screen for PT PE in the first trimester is potentially cost-effective in the Dutch healthcare setting. The fact that the specificity is a major driver of the ICER indicates the importance for a (new) screening model to correctly classify low-risk pregnancies.

Aspirin delays the onset of hypertensive disorders of pregnancy among nulliparous pregnant women: A secondary analysis of the ASPIRIN trial

OBJECTIVE

To assess the impact of low-dose aspirin (LDA) starting in early pregnancy on delaying preterm hypertensive disorders of pregnancy.

DESIGN

Non-prespecified secondary analysis of a randomised masked trial of LDA.

SETTING

The study was conducted among women in the Global Network for Women's and Children's Health's Maternal and Newborn Health Registry (MNHR) clusters, a prospective, population-based study in Kenya, Zambia, the Democratic Republic of the Congo (DRC), Pakistan, India (two sites-Belagavi and Nagpur) and Guatemala.

POPULATION

Nulliparous singleton pregnancies between 6+0 weeks and 13+6  weeks in six low-middle income countries (Democratic Republic of Congo, Guatemala, India, Kenya, Pakistan, Zambia) enrolled in the ASPIRIN Trial.

METHODS

We compared the incidence of HDP at delivery at three gestational age periods (<28, <34 and <37 weeks) between women who were randomised to aspirin or placebo. Women were included if they were randomised and had an outcome at or beyond 20 weeks (Modified Intent to Treat).

MAIN OUTCOME MEASURES

Our primary outcome was pregnancies with HDP associated with preterm delivery (HDP@delivery) before <28, <34 and <37 weeks. Secondary outcomes included small for gestational age (SGA) <10th percentile, <5th percentile, and perinatal mortality.

RESULTS

Among the 11 976 pregnancies, LDA did not significantly lower HDP@delivery <28 weeks (relative risk [RR] 0.18, 95% confidence interval [CI] 0.02-1.52); however, it did lower HDP@delivery <34 weeks (RR 0.37, 95% CI 0.17-0.81) and HDP@delivery <37 weeks (RR 0.66, 95% CI 0.49-0.90). The overall rate of HDP did not differ between the two groups (RR 1.08, 95% CI 0.94-1.25). Among those pregnancies who had HDP, SGA <10th percentile was reduced (RR 0.81, 95% CI 0.67-0.99), though SGA <5th percentile was not (RR 0.84, 95% CI 0.64-1.09). Similarly, perinatal mortality among pregnancies with HDP occurred less frequently (RR 0.55, 95% CI 0.33-0.92) in those receiving LDA. Pregnancies randomised to LDA delivered later with HDP compared with those receiving placebo (median gestational age 38.5 weeks vs. 37.9 weeks; p = 0.022).

CONCLUSIONS

In this secondary analysis of a study of low-risk nulliparous singleton pregnancies, early administration of LDA resulted in lower rates of preterm HDP and delivery before 34 and 37 weeks but not in the overall rate of HDP. These results suggest that LDA works in part by delaying HDP.

The great obstetrical syndromes and the placenta

Although historically pre-eclampsia, preterm birth, abruption, fetal growth restriction and stillbirth have been viewed as clinically distinct entities, a growing body of literature has demonstrated that the placenta and its development is the root cause of many cases of these conditions. This has led to the term 'the great obstetrical syndromes' being coined to reflect this common origin. Although these conditions mostly manifest in the second half of pregnancy, a failure to complete deep placentation (the transition from histiotrophic placentation to haemochorial placenta at 10-18 weeks of gestation via a second wave of extravillous trophoblast invasion), is understood to be key to the pathogenesis of the great obstetrical syndromes. While the reasons that the placenta fails to achieve deep placentation remain active areas of investigation, maternal inflammation and thrombosis have been clearly implicated. From a clinical standpoint these mechanisms provide a biological explanation of how low-dose aspirin, which affects the COX-1 receptor (thrombosis) and the COX-2 receptor (inflammation), prevents not just pre-eclampsia but all the components of the great obstetrical syndromes if initiated early in pregnancy. The optimal dose of low-dose aspirin that is maximally effective in pregnancy remains a question open for further research. Additionally, other candidate medications have been identified that may also prevent pre-eclampsia, and further study of them may offer therapeutic options beyond low-dose aspirin. Interestingly, three of the eight identified compounds (hydroxychloroquine, metformin and pravastatin) are known to decrease inflammation.

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.

The Role of Acetylsalicylic Acid in the Prevention of Pre-Eclampsia, Fetal Growth Restriction, and Preterm Birth

BACKGROUND

Recent studies suggest that low-dose acetylsalicylic acid (ASA) can lower pregnancy-associated morbidity.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in PubMed, with special attention to systematic reviews, metaanalyses, and randomized controlled trials.

RESULTS

Current meta-analyses document a reduction of the risk of the occurrence of pre-eclampsia (RR 0.85, NNT 50), as well as beneficial effects on the rates of preterm birth (RR 0.80, NNT 37), fetal growth restriction (RR 0.82, NNT 77), and perinatal death (RR 0.79, NNT 167). Moreover, there is evidence that ASA raises the rate of live births after a prior spontaneous abortion, while also lowering the rate of spontaneous preterm births (RR 0.89, NNT 67). The prerequisites for therapeutic success are an adequate ASA dose, early initiation of ASA, and the identification of women at risk of pregnancy-associated morbidity. Side effects of treatment with ASA in this patient group are rare and mainly involve bleeding in connection with the pregnancy (RR 0.87, NNH 200).

CONCLUSION

ASA use during pregnancy has benefits beyond reducing the risk of pre-eclampsia. The indications for taking ASA during pregnancy may be extended at some point in the future; at present, in view of the available evidence, it is still restricted to high-risk pregnancies.

Reconsidering the effectiveness of low-dose aspirin in prevention of pre-eclampsia among otherwise low risk twin gestations: A historical cohort study

OBJECTIVE

To investigate the effectiveness of low-dose aspirin (LDA) in the prevention of pre-eclampsia (PE) among otherwise low-risk twin gestations.

METHODS

A historical cohort study consisting of all pregnant individuals with dichorionic diamniotic (DCDA) twin pregnancy who delivered between 2014 and 2020. Patients treated with LDA were matched by a 1:4 ratio to individuals who were not treated with LDA by age, body mass index and parity.

RESULTS

During the study period, 2271 individuals carrying DCDA pregnancies delivered at our center. Of these, 404 were excluded for one or more additional major risk factors. The remaining cohort consisted of 1867 individuals of whom 142 (7.6%) were treated with LDA and were compared with a 1:4 matched group of 568 individuals who were not treated. The rate of preterm PE did not differ significantly between the two groups (18 [12.7%] in the LDA group vs. 55 [9.7%] in the no-LDA group; P = 0.294, adjusted odds ratio 1.36, 95% confidence interval 0.77-2.40). There were no other significant between-group differences.

CONCLUSIONS

Low-dose aspirin treatment in pregnant individuals with DCDA twin gestations without additional major risk factors was not associated with a reduction in the rate of preterm PE.

Evaluation of impacts of aspirin therapy versus placebo on preeclampsia: An observational study

Background

Gestational hypertension and pre-eclampsia often increase maternal and neonatal mortality. The illness usually appears after the 20th week of pregnancy due to malnutrition or obesity. Untreated, it can lead to neonatal and maternal mortality. Low-dose Aspirin can prevent preeclampsia if started between 11 and 28 weeks. Several studies support this technique, although others have shown limited effectiveness and negative side effects.

Objective

This study aims to assess the effectiveness of aspirin treatment for the prevention of preeclampsia, taking into account any possible adverse reactions.

Methods

This observational research comprised 600 singleton pregnant women at high risk of pregnancy-induced hypertension. The aspirin group had 301 individuals and the placebo group 299. From 11 to 36 weeks of pregnancy, they received 150 mg of aspirin and 150 mg of placebo. Gestational hypertension was assessed at 25 weeks, 36 weeks, and 37 weeks. If any, aspirin and placebo-related adverse pregnancy and neonatal outcomes were reported.

Results

With aspirin therapy, 4 females and 14 females with placebo developed gestational hypertension before 25 weeks of pregnancy with an odds ratio of 0.283 (0.092-0.87); before 36 weeks, 5 females and 15 females with placebo developed GHD with an odds ratio of 0.331 (0.118-0.922); and after 37 weeks, 17 females and 35 females with placebo developed GHD. Preeclampsia occurred in 5 females in the aspirin group and 17 in the placebo group at <25 weeks (odds ratio 0.292 (0.106-0.802), 7 females in the aspirin arm and 25 females in the placebo arm at <36 weeks (odds ratio 0.278 (0.118-0.652), and 21 females in the aspirin arm and 39 females in the placebo arm at >37 weeks (odds ratio 0.5349 (0.307-0.930).

Conclusion

In pregnant women at high risk of prenatal hypertension and preeclampsia, aspirin therapy is very effective with minimal side effects.

Machine-learning predictive model of pregnancy-induced hypertension in the first trimester

In the first trimester of pregnancy, accurately predicting the occurrence of pregnancy-induced hypertension (PIH) is important for both identifying high-risk women and adopting early intervention. In this study, we used four machine-learning models (LASSO logistic regression, random forest, backpropagation neural network, and support vector machines) to predict the occurrence of PIH in a prospective cohort. Candidate features for predicting the occurrence of middle and late PIH were acquired using a LASSO algorithm. The performance of predictive models was assessed using receiver operating characteristic analysis. Finally, a nomogram was established with the model scores, age, and nulliparity. Calibration, clinical usefulness, and internal validation were used to assess the performance of the nomogram. In the training set (2258 pregnant women), eleven candidate factors in the first trimester were significantly associated with the occurrence of PIH (P < 0.001 in the training set). Four models showed AUCs from 0.780 to 0.816 in the training set. For the validation set (939 pregnant women), AUCs varied from 0.516 to 0.795. The nomogram showed good discrimination, with an AUC of 0.847 (95% CI: 0.805-0.889) in the training set and 0.753 (95% CI: 0.653-0.853) in the validation set. Decision curve analysis suggested that the model was clinically useful. The model developed using LASSO logistic regression achieved the best performance in predicting the occurrence of PIH. The derived nomogram, which incorporates the model score and maternal risk factors, can be used to predict PIH in clinical practice. We develop a model with good performance for clinical prediction of PIH in the first trimester.

First-trimester screening for Down syndrome using quadruple maternal biochemical markers

OBJECTIVES

Placental growth factor (PlGF) is used for first-trimester preeclampsia screening and could be combined with other biochemical markers for Down syndrome screening. We aim to estimate the predictive value of the combination of pregnancy-associated plasma protein (PAPP-A), free β-human chorionic gonadotropin (free β-hCG), placental growth factor (PlGF) and α-fetoprotein (AFP) with and without nuchal translucency.

METHODS

Singleton pregnancies recruited at 11-14 weeks and followed until delivery. The four maternal markers were measured using Kryptor (ThermoFisher-BRAHMS) and adjusted for gestational age and maternal characteristics. The risk of Down syndrome was calculated using the Fetal Medicine Foundation algorithm and multivariate linear regression analyses in all cases and in 2,200 controls. Receiver-operator characteristic (ROC) curves were used to calculate the detection and false-positive rates.

RESULTS

Twenty-six (0.2%) cases of Down syndrome were diagnosed among 13,386 participants. The combination of the four biomarkers could have detected 88% (95% CI: 72-97%) of the cases at a false-positive rate of 13% (95% CI: 12-15%). The addition of nuchal translucency would have increased the detection rate to 96% (95% CI: 82-99%) at a false-positive rate of 4% (95% CI: 4-5%) using a 1:300 cut-off and to 100% (95% CI: 89-100%) at a false-positive rate of 6% (95% CI: 5-8%) using a 1:500 cut-off.

CONCLUSIONS

First-trimester screening using biochemical markers allows the identification of approximately 88% of Down syndrome cases for a false-positive rate of 13%. The addition of nuchal translucency raises the detection rate above 95% with a false-positive rate below 5%.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

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

BACKGROUND

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.

OBJECTIVES

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.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSION

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.

Stillbirth: prevention and supportive bereavement care

Around half of the two million stillbirths occurring worldwide each year are preventable. This review compiles the most up-to-date evidence to inform stillbirth prevention. Many general maternal health interventions also reduce the risk of stillbirth, for example, antenatal care attendance. This review focuses on specific aspects of care: glucose metabolism, targeted aspirin prophylaxis, clotting and immune disorders, sleep positions, fetal movement monitoring, and preconception and interconception health. In the past few years, covid-19 infection during pregnancy has emerged as a risk factor for stillbirth, particularly among women who were not vaccinated. Alongside prevention, efforts to address stillbirth must include provision of high quality, supportive, and compassionate bereavement care to improve parents' wellbeing. A growing body of evidence suggests beneficial effects for parents who received supportive care and were offered choices such as mode of birth and the option to see and hold their baby. Staff need support to be able to care for parents effectively, yet, studies consistently highlight the scarcity of specific bereavement care training for healthcare providers. Action is urgently needed and is possible. Action must be taken with the evidence available now, in healthcare settings with high or low resources, to reduce stillbirths and improve training and care.

The SPROUT study: A survey on current management practice of reproductive aspects in women of childbearing age with systemic autoimmune rheumatic diseases

The SPROUT (Survey on reproduction in RheUmaTology) study explored current practice in women of childbearing age with systemic autoimmune rheumatic diseases, investigating the counselling on contraception, the prescription of low dose acetylsalicylic acid (LDASA) to pregnant patients and the management of disease activity in the post-partum period. The SPROUT questionnaire was designed ad hoc and promoted in the three months before the "11^th International Conference on Reproduction, Pregnancy and Rheumatic Disease". Between June and August 2021, 121 physicians responded to the survey. Even though 66.8% of the participants declared themselves to be confident in counselling surrounding birth control, only 62.8% of physicians always discuss contraception and family planning with women of childbearing age. Approximately 20% of respondents do not prescribe LDASA to pregnant women with rheumatic diseases, and wide heterogeneity exists in the dose and timing of LDASA prescription. Most respondents (43.8%) restart treatment with biological agents soon after delivery to prevent disease flares, opting for a drug compatible with breastfeeding while 41.3% of physicians continue biologics throughout pregnancy and post-partum. The SPROUT study highlighted the necessity to further foster physicians' education and identified the management of disease activity after delivery as a matter for discussion between all the clinicians involved in the care of pregnant women with rheumatic conditions.

Prevention of pre-eclampsia with aspirin: A systematic review of guidelines and evaluation of the quality of recommendation evidence

BACKGROUND

Evidence has shown significant benefits of aspirin for preventing pre-eclampsia.

OBJECTIVES

The objective of this study was to systematically review recommendations from clinical practice guidelines and other recommendation documents on aspirin for the prevention of pre-eclampsia.

SEARCH STRATEGY

Ten databases were searched for statements from December 1, 2013, to January 1, 2022.

SELECTION CRITERIA

Without language restrictions, the most recent version of documents was considered.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted recommendations. Guideline quality was assessed using a modified AGREE-II instrument and the AGREE-REX tool.

MAIN RESULTS

Out of 48 statements on the prevention of pre-eclampsia, 46 had recommendations on use of aspirin. Of them, 39 were supported by evidence from systematic reviews or randomized controlled trials. Three statements reported aspirin's significant reductions in preterm pre-eclampsia and one in perinatal death. Concerning quality, 41% of statements were rated as high quality in all domains of the AGREE-II tool, 15% were rated high quality in all domains of the AGREE-REX tool, and 11% were rated high quality in all domains on both tools.

CONCLUSIONS

While 96% of statements advocated for use of aspirin, only 9% reported a significant reduction in preterm pre-eclampsia or perinatal death. Based on the AGREE tools, future statements could use methodological improvement.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

High concentration of first-measured HCG after embryo transfer is associated with subsequent development of pre-eclampsia

RESEARCH QUESTION

Are outlier high values of first-measured human chorionic gonadotrophin (HCG) following embryo transfer related to pregnancy complications, specifically pre-eclampsia?

DESIGN

This retrospective cohort study screened 3448 women aged 18-45 years who underwent IVF between 2014 and 2019 and evaluated 614 women who had an intrauterine pregnancy following single embryo transfer (SET), 423 of whom had a live birth. Pregnancy and birth outcome information was available for final analysis in 280 cases. The setting was a university-based IVF centre. HCG was measured at a standardized time after the embryo transfer and the values correlated with adverse pregnancy outcomes associated with poor placentation.

RESULTS

Women with first-measured HCG in the highest quintile had a higher incidence of pre-eclampsia than those with lower HCG concentrations (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.41-11.82) even after controlling for age, body mass index, parity and type of embryo transfer. Additionally controlling for embryo stage at embryo transfer did not change the results (OR 3.97, 95% CI 1.37-11.46). No differences were found in the incidence of fetal growth restriction.

CONCLUSIONS

This is the first known report that links high first-measured HCG after SET to an adverse pregnancy outcome. If confirmed by future studies, initiation of preventive interventions at a very early stage of pregnancy merits further evaluation in this cohort of patients.

The effect of 150 and 80 mg doses of aspirin on preventing preterm birth in high-risk pregnant women

OBJECTIVES

Preterm birth (PTB) is the common cause of neonatal mortality nationwide. The present study aimed to evaluate the efficacy of different doses of aspirin in preventing PTB in high-risk pregnant women. As secondary outcomes, other perinatal complications were compared.

METHODS

This double-blind randomized clinical trial was conducted on high-risk pregnant women with impaired placental perfusion diagnosed in the first trimester of pregnancy referring to the perinatal centers affiliated to Shiraz university of Medical Sciences between February 2020 and March 2021. The subjects were randomly divided in two groups administered with 150 or 80 mg aspirin every night from 11 to 13+6 weeks until 36 weeks or delivery. This study is registered in the Iranian Registry of Clinical Trials (IRCT20140317017035N6; http://www.irct.ir/). Univariate and multiple logistic regressions were applied using SPSS 22.

RESULTS

A total of 101 subjects received 80 mg aspirin and 89 ones received 150 mg aspirin. The results of multiple analysis revealed a significantly lower odds of PTB (OR 0.4 (0.19, 0.99)) in the 150 mg group compared to the 80 mg group. As secondary outcomes, preeclampsia (PEC) and PEC with severe features (PECsf) were lower (OR 0.2 (0.06, 0.82) and 0.1 (0.01, 0.92), respectively); however, fetal age and neonatal weight were higher in the 150 mg group (OR 1.2 (1.04, 1.33) and 1.001 (1-1.001), respectively).

CONCLUSIONS

The study findings indicated that, compared with 80 mg of aspirin, taking 150 mg of aspirin reduced PTB and perinatal complications in high risk pregnant women.

Improved implementation of aspirin in pregnancy among Dutch gynecologists: Surveys in 2016 and 2021

Objective

To evaluate the implementation of low-dose aspirin in pregnancy for the prevention of utero-placental complications among gynecologists in the Netherlands between 2016 and 2021. In this timeframe, a national guideline about aspirin in pregnancy was introduced by the Dutch Society of Obstetrics and Gynecology.

Materials and methods

A national online survey among Dutch gynecologists and residents was performed. An online questionnaire was distributed among the members of the Dutch Society of Obstetrics and Gynecology in April 2016 and April 2021. Main outcome measure was the proportion of gynecologists indicating prescription of aspirin in pregnancy for high and moderate risk indications.

Results

In 2016, 133 respondents completed the survey, and in 2021 231. For all indications mentioned in the guideline there was an increase in prescribing aspirin in 2021 in comparison to 2016. More specifically, the percentage of gynecologists prescribing aspirin for a history of preeclampsia before 34 weeks, between 34 and 37 weeks and at term increased from respectively 94% to 100%, 39% to 98%, and 15% to 97%. Consultant obstetricians and respondents working in an university hospital did not more often indicate the prescription of aspirin for tertiary care indications in 2021. Future use of a prediction model was suggested in the narrative comments.

Conclusion

Implementation of aspirin in pregnancy among Dutch gynecologists substantially improved after a five year timeframe in which the national guideline on aspirin during pregnancy was introduced and trials confirming the effect of aspirin were published.

Fully Automated Placental Volume Quantification From 3D Ultrasound for Prediction of Small-for-Gestational-Age Infants

OBJECTIVES

Early placental volume (PV) has been associated with small-for-gestational-age infants born under the 10th/5th centiles (SGA10/SGA5). Manual or semiautomated PV quantification from 3D ultrasound (3DUS) is time intensive, limiting its incorporation into clinical care. We devised a novel convolutional neural network (CNN) pipeline for fully automated placenta segmentation from 3DUS images, exploring the association between the calculated PV and SGA.

METHODS

Volumes of 3DUS obtained from singleton pregnancies at 11-14 weeks' gestation were automatically segmented by our CNN pipeline trained and tested on 99/25 images, combining two 2D and one 3D models with downsampling/upsampling architecture. The PVs derived from the automated segmentations (PV_CNN ) were used to train multivariable logistic-regression classifiers for SGA10/SGA5. The test performance for predicting SGA was compared to PVs obtained via the semiautomated VOCAL (GE-Healthcare) method (PV_VOCAL ).

RESULTS

We included 442 subjects with 37 (8.4%) and 18 (4.1%) SGA10/SGA5 infants, respectively. Our segmentation pipeline achieved a mean Dice score of 0.88 on an independent test-set. Adjusted models including PV_CNN or PV_VOCAL were similarly predictive of SGA10 (area under curve [AUC]: PV_CNN  = 0.780, PV_VOCAL  = 0.768). The addition of PV_CNN to a clinical model without any PV included (AUC = 0.725) yielded statistically significant improvement in AUC (P < .05); whereas PV_VOCAL did not (P = .105). Moreover, when predicting SGA5, including the PV_CNN (0.897) brought statistically significant improvement over both the clinical model (0.839, P = .015) and the PV_VOCAL model (0.870, P = .039).

CONCLUSIONS

First trimester PV measurements derived from our CNN segmentation pipeline are significantly associated with future SGA. This fully automated tool enables the incorporation of including placental volumetric biometry into the bedside clinical evaluation as part of a multivariable prediction model for risk stratification and patient counseling.

The efficacy of low-dose aspirin in pregnancy among women in malaria-endemic countries

BACKGROUND

Low dose aspirin (LDA) is an effective strategy to reduce preterm birth. However, LDA might have differential effects globally, based on the etiology of preterm birth. In some regions, malaria in pregnancy could be an important modifier of LDA on birth outcomes and anemia.

METHODS

This is a sub-study of the ASPIRIN trial, a multi-national, randomized, placebo controlled trial evaluating LDA effect on preterm birth. We enrolled a convenience sample of women in the ASPIRIN trial from the Democratic Republic of Congo (DRC), Kenya and Zambia. We used quantitative polymerase chain reaction to detect malaria. We calculated crude prevalence proportion ratios (PRs) for LDA by malaria for outcomes, and regression modelling to evaluate effect measure modification. We evaluated hemoglobin in late pregnancy based on malaria infection in early pregnancy.

RESULTS

One thousand four hundred forty-six women were analyzed, with a malaria prevalence of 63% in the DRC site, 38% in the Kenya site, and 6% in the Zambia site. Preterm birth occurred in 83 (LDA) and 90 (placebo) women, (PR 0.92, 95% CI 0.70, 1.22), without interaction between LDA and malaria (p = 0.75). Perinatal mortality occurred in 41 (LDA) and 43 (placebo) pregnancies, (PR 0.95, 95% CI 0.63, 1.44), with an interaction between malaria and LDA (p = 0.014). Hemoglobin was similar by malaria and LDA status.

CONCLUSIONS

Malaria in early pregnancy did not modify the effects of LDA on preterm birth, but modified the effect of LDA on perinatal mortality. This effect measure modification deserves continued study as LDA is used in malaria endemic regions.

A Review of Roles of Uterine Artery Doppler in Pregnancy Complications

The invasion of trophoblasts into the uterine decidua and decidual vessels is critical for the formation of placenta. The defects of placentation are related to the etiologies of preeclampsia (PE), fetal growth restriction (FGR), and small-for-gestational age (SGA) neonates. It is possible to predict significant vascular events during pregnancy through uterine artery Doppler (UAD). From the implantation stage to the end of pregnancy, detecting changes in uterine and placental blood vessels can provide a favorable diagnostic instrument for pregnancy complications. This review aims to collect literature about the roles of UAD in pregnancy complications. We consider all relevant articles in English from January 1, 1983 to October 30, 2021. Predicting pregnancy complications in advance allows practitioners to carry out timely interventions to avoid or lessen the harm to mothers and neonates. Administering low-dose aspirin daily before 16 weeks of pregnancy can significantly reduce the incidence of pregnancy complications. From early pregnancy to late pregnancy, UAD can combine with other maternal factors, biochemical indicators, and fetal measurement data to identify high-risk population. The identification of high-risk groups can also lessen maternal mortality. Besides, through moderate risk stratification, stringent monitoring for high-risk pregnant women can be implemented, decreasing the incidence of adversities.

Kidney graft function before pregnancy as a predictor of graft, maternal and fetal outcomes in pregnant renal transplant recipients

OBJECTIVES

Maternal and fetal complications can occur in pregnant kidney transplant recipients. Since these are high-risk pregnancies, they require a multidisciplinary follow-up to prematurely detect adverse events. Identifying factors that would affect fetal, maternal and graft outcomes is essential to further stratify the risk of pregnant kidney transplant recipients.

METHODS

All pregnancies in kidney transplant recipients followed in a single center for 30 years were included. Data included previous transplant information and blood and urine tests performed before pregnancy. Impact of graft function on fetal, maternal and graft outcomes was evaluated.

RESULTS

There were 41 pregnancies among 34 patients. Mean gestational age of 35 ± 3 weeks. Caesarean section was performed in 69.4% of patients. Five pregnancies were unsuccessful (12.2%). Four patients suffered an acute graft dysfunction (9.8%) and 12 (29.3%) had a serious maternal hypertensive disorder (preeclampsia, eclampsia or HELLP syndrome). Graft function before pregnancy showed significant correlation with adverse outcomes.

CONCLUSIONS

A proteinuria >669 mg/g, serum creatinine >1.75 mg/dL and glomerular filtration rate <36.2 mL/min/1.73 m² before pregnancy were correlated to graft dysfunction during pregnancy. Similar values of proteinuria were also associated with a risk of maternal hypertensive disorders and pregnancy failure. Therefore, in patients with proteinuria and graft dysfunction, follow-up should be stricter to quickly detect complications.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

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.

Prediction of pre-eclampsia

Pre-eclampsia is a leading cause of neonatal and maternal mortality and morbidity that complicates approximately 2-8% of all pregnancies worldwide. The precise cause of pre-eclampsia is not completely understood, with several environmental, genetic, and maternal factors involved in its pathogenesis and pathophysiology. An accurate predictor of pre-eclampsia will facilitate early recognition, close surveillance according to the individual risk and early intervention, and reduce the negative consequences of the disorder. Current evidence shows that no single test predicts pre-eclampsia with sufficient accuracy to be clinically useful. A combination of markers into multiparametric models may provide a more useful and feasible predictive tool for pre-eclampsia screening in the routine care setting than a test of either component alone. This review presents a summary of the current advances on prediction of pre-eclampsia, highlighting their performance and applicability. Key priorities when conducting research on predicting pre-eclampsia are also analyzed.