Low-dose aspirin to prevent preeclampsia in women at high risk. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

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.

Hypertensive Disorders of Pregnancy: Diagnosis, Management and Timing of Birth

Hypertensive disorders of pregnancy are significant contributors to maternal and perinatal morbidity and mortality. The definition, classification, and management of these disorders have evolved over time. Notably, the disease classification enables caretakers to manage the disease as well as safeguard maternal and fetal health. The approach and management for pregnancies with gestational and chronic hypertension or pre-eclampsia with or without severe features should be adequately elucidated to mitigate adverse perinatal outcomes. This review aimed to present the most recent definition and classification of hypertensive disorders of pregnancy to address their management, determine the optimal timing of birth, and establish short- and long-term follow-up protocols following parturition.

Aspirin resistance in pregnancy is associated with reduced interleukin-2 (IL-2) concentrations in maternal serum: Implications for aspirin prophylaxis for preeclampsia

OBJECTIVES

To evaluate the impact of aspirin resistance on the incidence of preeclampsia and maternal serum biomarker levels in pregnant individuals at high-risk of preeclampsia receiving low dose aspirin (LDA).

STUDY DESIGN

We performed a secondary analysis of a randomized, placebo-controlled trial of LDA (60 mg daily) for preeclampsia prevention in high-risk individuals (N = 524) on pregnancy outcomes and concentrations of PLGF, IL-2, IL-6, thromboxane B2 (TXB2), sTNF-R1 and sTNF-R2 from maternal serum.

MAIN OUTCOME MEASURES

LDA-resistant individuals were defined as those having a TXB2 concentration >10 ng/ml or <75 % reduction in concentration at 24-28 weeks after LDA administration. Comparisons of outcomes were performed using a Fisher's Exact Test. Mean concentrations of maternal serum biomarkers were compared using a Student's t-test. Pearson correlation was calculated for all pairwise biomarkers. Longitudinal analysis across gestation was performed using linear mixed-effects models accounting for repeated measures and including BMI and maternal age as covariates.

RESULTS

We classified 60/271 (22.1 %) individuals as LDA-resistant, 179/271 (66.1 %) as LDA-sensitive, and 32/271 (11.8 %) as non-adherent. The prevalence of preeclampsia was not significantly different between the LDA and placebo groups (OR = 1.43 (0.99-2.28), p-value = 0.12) nor between LDA-sensitive and LDA-resistant individuals (OR = 1.27 (0.61-2.8), p-value = 0.60). Mean maternal serum IL-2 concentrations were significantly lower in LDA-resistant individuals relative to LDA-sensitive individuals (FDR < 0.05).

CONCLUSIONS

These results suggest a potential role for IL-2 in the development of preeclampsia modulated by an individuals' response to aspirin, presenting an opportunity to optimize aspirin prophylaxis on an individual level to reduce the incidence of preeclampsia.

Development and validation of prediction models for fetal growth restriction and birthweight: an individual participant data meta-analysis

Background

Fetal growth restriction is associated with perinatal morbidity and mortality. Early identification of women having at-risk fetuses can reduce perinatal adverse outcomes.

Objectives

To assess the predictive performance of existing models predicting fetal growth restriction and birthweight, and if needed, to develop and validate new multivariable models using individual participant data.

Design

Individual participant data meta-analyses of cohorts in International Prediction of Pregnancy Complications network, decision curve analysis and health economics analysis.

Participants

Pregnant women at booking. External validation of existing models (9 cohorts, 441,415 pregnancies); International Prediction of Pregnancy Complications model development and validation (4 cohorts, 237,228 pregnancies).

Predictors

Maternal clinical characteristics, biochemical and ultrasound markers.

Primary outcomes

fetal growth restriction defined as birthweight <10th centile adjusted for gestational age and with stillbirth, neonatal death or delivery before 32 weeks' gestation birthweight.

Analysis

First, we externally validated existing models using individual participant data meta-analysis. If needed, we developed and validated new International Prediction of Pregnancy Complications models using random-intercept regression models with backward elimination for variable selection and undertook internal-external cross-validation. We estimated the study-specific performance (c-statistic, calibration slope, calibration-in-the-large) for each model and pooled using random-effects meta-analysis. Heterogeneity was quantified using τ2 and 95% prediction intervals. We assessed the clinical utility of the fetal growth restriction model using decision curve analysis, and health economics analysis based on National Institute for Health and Care Excellence 2008 model.

Results

Of the 119 published models, one birthweight model (Poon) could be validated. None reported fetal growth restriction using our definition. Across all cohorts, the Poon model had good summary calibration slope of 0.93 (95% confidence interval 0.90 to 0.96) with slight overfitting, and underpredicted birthweight by 90.4 g on average (95% confidence interval 37.9 g to 142.9 g). The newly developed International Prediction of Pregnancy Complications-fetal growth restriction model included maternal age, height, parity, smoking status, ethnicity, and any history of hypertension, pre-eclampsia, previous stillbirth or small for gestational age baby and gestational age at delivery. This allowed predictions conditional on a range of assumed gestational ages at delivery. The pooled apparent c-statistic and calibration were 0.96 (95% confidence interval 0.51 to 1.0), and 0.95 (95% confidence interval 0.67 to 1.23), respectively. The model showed positive net benefit for predicted probability thresholds between 1% and 90%. In addition to the predictors in the International Prediction of Pregnancy Complications-fetal growth restriction model, the International Prediction of Pregnancy Complications-birthweight model included maternal weight, history of diabetes and mode of conception. Average calibration slope across cohorts in the internal-external cross-validation was 1.00 (95% confidence interval 0.78 to 1.23) with no evidence of overfitting. Birthweight was underestimated by 9.7 g on average (95% confidence interval -154.3 g to 173.8 g).

Limitations

We could not externally validate most of the published models due to variations in the definitions of outcomes. Internal-external cross-validation of our International Prediction of Pregnancy Complications-fetal growth restriction model was limited by the paucity of events in the included cohorts. The economic evaluation using the published National Institute for Health and Care Excellence 2008 model may not reflect current practice, and full economic evaluation was not possible due to paucity of data.

Future work

International Prediction of Pregnancy Complications models' performance needs to be assessed in routine practice, and their impact on decision-making and clinical outcomes needs evaluation.

Conclusion

The International Prediction of Pregnancy Complications-fetal growth restriction and International Prediction of Pregnancy Complications-birthweight models accurately predict fetal growth restriction and birthweight for various assumed gestational ages at delivery. These can be used to stratify the risk status at booking, plan monitoring and management.

Study registration

This study is registered as PROSPERO CRD42019135045.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/148/07) and is published in full in Health Technology Assessment; Vol. 28, No. 14. See the NIHR Funding and Awards website for further award information.

Preeclampsia epidemiology(ies) and pathophysiology(ies)

Preeclampsia/eclampsia was first described 2000 years ago. Concepts guiding diagnosis have changed over time making longitudinal studies challenging. Similarly, concepts of pathophysiology have evolved from eclampsia as a pregnancy seizure disorder to preeclampsia as a hypertensive and renal disorder to our current concept of a preeclampsia as a pregnancy specific, multisystemic inflammatory disorder. Although preeclampsia is pregnancy specific and many pathophysiologic findings begin to resolve with delivery, its impact extends beyond pregnancy. The risk of cardiovascular and neurological disease is increased after pregnancy in women who have had preeclampsia. The disorder is not a disease, but a syndrome and emerging data indicate multiple pathways to the syndrome. It is likely that our failure to have a major impact on prediction and prevention despite a large increase in understanding is due to the existence of multiple subtypes of preeclampsia. This concept should guide future research.

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.

Evaluation of Low-Dose Aspirin to Prevent Preeclampsia in Pregnant People with Chronic Hypertension

OBJECTIVE

Our objective was to evaluate if the use of low-dose aspirin (LDA) among pregnant individuals with chronic hypertension (CHTN) reduces the rate of superimposed preeclampsia or other adverse maternal and neonatal outcomes.

STUDY DESIGN

Our study included single-center cohort of pregnant individuals with CHTN who had a live birth after 23 weeks' gestation, between 2013 and 2018. The primary exposure was the use of LDA in pregnancy and the primary outcome was superimposed preeclampsia. LDA use was also evaluated by the timing of initiation, before or after 16 weeks' gestation. Secondary outcomes included preeclampsia subtypes (e.g., preeclampsia with severe features, early-onset disease), as well as adverse maternal and neonatal outcomes. Differences were analyzed by χ 2, Fisher's exact, or t tests, with logistic regression to adjust for confounders.

RESULTS

Of 11,825 deliveries during the study period, 494 (4.2%) occurred in women with CHTN. Among those with CHTN, 174 (35%) were prescribed LDA, most often 81 mg daily (173 out of 174, 99%). Baseline characteristics were similar between groups, but the history of preeclampsia was more common in those prescribed LDA. The rate of superimposed preeclampsia was no different among those with CHTN-prescribed LDA compared with those who were not (36% vs. 30%, p = 0.2), even when restricting the analysis to those prescribed LDA before 16 weeks' gestation (33 vs. 30%, p = 0.2). In addition, LDA did not lead to a reduction in the rate of preeclampsia with severe features, early-onset preeclampsia, or other adverse maternal outcomes. However, the composite rate of adverse neonatal outcomes was lower in LDA users versus nonusers (4.0 vs. 13%, p = 0.002), which persisted after multivariable adjustment (adjusted odds ratio: 0.28, 95% confidence interval: 0.12-0.67).

CONCLUSION

Among pregnant individuals with CHTN, LDA did not decrease the rate of superimposed preeclampsia. Further studies are warranted to validate our observed reduction in adverse neonatal outcomes and to determine if aspirin is more beneficial at dosages greater than 81 mg daily.

KEY POINTS

· Superimposed preeclampsia rates are the same regardless of LDA.. · Decreased rate of adverse neonatal outcomes is seen with LDA.. · No decrease in adverse maternal outcomes is seen with LDA..

The optimal dosage of aspirin for preventing preeclampsia in high-risk pregnant women: A network meta-analysis of 23 randomized controlled trials

This study aimed to assess the effectiveness and optimal dosage of aspirin in preventing preeclampsia in high-risk pregnant women. Traditional and network meta-analyses were conducted on data from 23 randomized controlled trials involving 10 547 pregnant women. The findings demonstrated that aspirin significantly reduced the incidence of preeclampsia (OR = 0.66, 95%CI [0.58, 0.75]), with the best preventive effect observed at a dosage of 80-100 mg/day (OR = 0.51, 95%CI [0.36, 0.72]). No significant differences were found in the occurrence of postpartum hemorrhage (OR = 1.03, 95%CI [0.79, 1.33]), small for gestational age (OR = 0.83, 95%CI [0.50, 1.35]), placental abruption (OR = 0.96, 95%CI [0.53, 1.73]), and intrauterine growth restriction (OR = 0.63, 95%CI [0.45, 1.86]) between women taking aspirin and those taking placebos. Different doses of aspirin showed a reduction in preeclampsia incidence, but there was no significant difference in efficacy between the dosage groups. Side effects did not significantly differ between placebo and different aspirin dosage groups. SUCRA analysis suggested that 80-100 mg/day may be the optimal dosage, prioritizing both effectiveness and minimizing side effects. Sensitivity analysis confirmed the robustness of the findings. However, improvements are needed in addressing issues like loss to follow-up, reporting bias, and publication bias. In conclusion, a dosage of 80-100 mg/day is recommended for preventing preeclampsia in high-risk pregnant women, although individual circumstances should be considered for optimizing the balance between effectiveness and safety.

The IRELAnD study-investigating the role of early low-dose aspirin in diabetes mellitus: a double-blinded, placebo-controlled, randomized trial

BACKGROUND

Although aspirin therapy is being increasingly advocated with the intention of risk modification for a wide range of pregnancy complications, women with prepregnancy diabetes mellitus are commonly excluded from clinical trials.

OBJECTIVE

The primary aim of this study was to examine the effect of aspirin therapy on a composite measure of adverse perinatal outcome in pregnancies complicated by pregestational diabetes mellitus.

STUDY DESIGN

A double-blinded, placebo-controlled randomized trial was conducted at 6 university-affiliated perinatology centers. Women with type 1 diabetes mellitus or type 2 diabetes mellitus of at least 6 months' duration were randomly allocated to 150-mg daily aspirin or placebo from 11 to 14 weeks' gestation until 36 weeks. Established vascular complications of diabetes mellitus, including chronic hypertension or nephropathy, led to exclusion from the trial. The primary outcome was a composite measure of placental dysfunction (preeclampsia, fetal growth restriction, preterm birth <34 weeks' gestation, or perinatal mortality). The planned sample size was 566 participants to achieve a 35% reduction in the primary outcome, assuming 80% statistical power. Secondary end points included maternal and neonatal outcomes and determination of insulin requirements across gestation. Data were centrally managed using ClinInfo and analyzed using SAS 9.4. The 2 treatment groups were compared using t tests or chi-square tests, as required, and longitudinal data were compared using a repeated-measures analysis.

RESULTS

From February 2020 to September 2022, 191 patients were deemed eligible, 134 of whom were enrolled (67 randomized to aspirin and 67 to placebo) with a retrospective power of 64%. A total of 101 (80%) women had type 1 diabetes mellitus and 25 (20%) had type 2 diabetes mellitus. Reaching the target sample size was limited by the impact of the COVID-19 pandemic. Baseline characteristics were similar between the aspirin and placebo groups. Treatment compliance was very high and similar between groups (97% for aspirin, 94% for placebo). The risk of the composite measure of placental dysfunction did not differ between groups (25% aspirin vs 21% placebo; P=.796). Women in the aspirin group had significantly lower insulin requirements throughout pregnancy compared with the placebo group. Insulin requirements in the aspirin group increased on average from 0.7 units/kg at baseline to 1.1 units/kg by 36 weeks' gestation (an average 83% within-patient increase), and increased from 0.7 units/kg to 1.3 units/kg (a 181% within-patient increase) in the placebo group, over the same gestational period (P=.002). Serial hemoglobin A1c levels were lower in the aspirin group than in the placebo group, although this trend did not reach statistical significance.

CONCLUSION

In this multicenter, double-blinded, placebo-controlled randomized trial, aspirin did not reduce the risk of adverse perinatal outcome in pregnancies complicated by prepregnancy diabetes mellitus. Compared with the placebo group, aspirin-treated patients required significantly less insulin throughout pregnancy, indicating a beneficial effect of aspirin on glycemic control. Aspirin may exert a plausible placenta-mediated effect on pregestational diabetes mellitus that is not limited to its antithrombotic properties.

Investigating the blood rheology in the first trimester pregnancies with high risk for preeclampsia

BACKGROUND

Pregnancy is a dynamic process associated with changes in vascular and rheological resistance. Maternal maladaptation to these changes is the leading cause of pregnancy complications such as preeclampsia.

OBJECTIVE

This study aimed to assess the hemorheological alterations in pregnancies with a high risk for preeclampsia in the first trimester.

METHODS

Ninety-two pregnant women were allocated into the high preeclampsia risk group (37 cases) and control groups (55 cases). Plasma and whole blood viscosity and red blood cell morphodynamic properties, including deformability and aggregation were assessed by Brookfield viscometer and laser-assisted optical rotational cell analyzer (LORRCA) at 11-14 gestational weeks.

RESULTS

Whole blood viscosity was significantly higher in the high-risk group at all shear rates. Plasma viscosity and hematologic factors showed no differences between the groups. Hematocrit levels positively correlated with high blood viscosity only in the high-risk group. There were no significant changes in the other deformability and aggregation parameters.

CONCLUSIONS

Changes in the whole blood viscosity of pregnant women with high preeclampsia risk refer to impaired microcirculation beginning from the early weeks of gestation. We suggest that the whole blood viscosity is consistent with the preeclampsia risk assessment in the first trimester, and its measurement might be promising for identifying high-preeclampsia-risk pregnancies.

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.

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.

Bell's palsy in pregnancy: A scoping review of risk factors, treatment and outcomes

Objective

There are limited studies reporting on Bell's palsy and pregnancy. Our study aimed to evaluate risk factors, current treatment options and facial function outcomes in women who developed Bell's palsy in pregnancy. To our knowledge this is the first review analyzing these factors.

Data sources/review methods

A search of PubMed/MEDLINE, Embase, Web of Sciences and Scopus was carried out. Studies describing risk factors, treatment and/or facial function outcomes of Bell's palsy in pregnancy were included. PRISMA-Scr guidelines were followed.

Results

The search yielded 392 abstracts, of which 15 studies were included for analysis. It was not possible to perform a meta-analysis due to small numbers and quality of studies. There were 559 patients included from the 15 studies. The third trimester was the most common time for Bell's palsy to occur (n = 364, 65%). Pre-eclampsia was the most common co-morbidity reported. The most common treatment was corticosteroids and the majority of patients had a complete recovery of their palsy (58%, n = 192).

Conclusion

This analysis has evaluated all available data concerning risk factors, treatment and facial function outcomes of BP in pregnancy. The third trimester is the most common time for Bell's palsy to occur in pregnancy. There is currently a lack of high quality evidence into this condition in pregnancy.

Level of evidence

1.

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

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

Low-Dose Aspirin during Pregnancy and Postpartum Bleeding

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

KEY POINTS

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

The 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.

Care plan for individuals at risk for preeclampsia: shared approach to education, strategies for prevention, surveillance, and follow-up

Preeclampsia is a multisystemic disorder of pregnancy that affects 250,000 pregnant individuals in the United States and approximately 10 million worldwide per annum. Preeclampsia is associated with substantial immediate morbidity and mortality but also long-term morbidity for both mother and offspring. It is now clearly established that a low dose of aspirin given daily, beginning early in pregnancy modestly reduces the occurrence of preeclampsia. Low-dose aspirin seems safe, but because there is a paucity of information about long-term effects on the infant, it is not recommended for all pregnant individuals. Thus, several expert groups have identified clinical factors that indicate sufficient risk to recommend low-dose aspirin preventive therapy. These risk factors may be complemented by biochemical and/or biophysical tests that either indicate increased probability of preeclampsia in individuals with clinical risk factors, or more importantly, identify increased likelihood in those without other evident risk. In addition, the opportunity exists to provide this population with additional care that may prevent or mitigate the short- and long-term effects of preeclampsia. Patient and provider education, increased surveillance, behavioral modification, and other approaches to improve outcomes in these individuals can improve the chance of a healthy outcome. We assembled a group with diverse, relevant expertise (clinicians, investigators, advocates, and public and private stakeholders) to develop a care plan in which providers and pregnant individuals at risk can work together to reduce the risk of preeclampsia and associated morbidities. The plan is for care of individuals at moderate to high risk for developing preeclampsia, sufficient to receive low-dose aspirin therapy, as identified by clinical and/or laboratory findings. The recommendations are presented using the GRADE methodology with the quality of evidence upon which each is based. In addition, printable appendices with concise summaries of the care plan's recommendations for patients and healthcare providers are provided. We believe that this shared approach to care will facilitate prevention of preeclampsia and its attendant short- and long-term morbidity in patients identified as at risk for development of this disorder.

Optimizing preconception care and interventions for improved population health

There is growing literature indicating that optimal preconception health is associated with improved reproductive, perinatal, and pediatric outcomes. Given that preconception care is recommended for all individuals planning a pregnancy, medical providers and public health practitioners have a unique opportunity to optimize care and improve health outcomes for reproductive-aged individuals. Knowledge of the determinants of preconception health is important for all types of health professionals, including policy makers. Although some evidence-based recommendations have already been implemented, additional research is needed to identify factors associated with favorable health outcomes and to ensure that effective interventions are made in a timely fashion. Given the largely clinical readership of this journal, this piece is primarily focused on clinical care. However, we acknowledge that optimizing preconception health for the entire population at risk of pregnancy requires broadening our strategies to include population-health interventions that consider the larger social systems, structures, and policies that shape individual health outcomes.

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.

Prediction and prevention of preeclampsia in women with preexisting diabetes: the role of home blood pressure, physical activity, and aspirin

Women with type 1 or type 2 (preexisting) diabetes are four times more likely to develop preeclampsia compared with women without diabetes. Preeclampsia affects 9%-20% of pregnant women with type 1 diabetes and 7%-14% of pregnant women with type 2 diabetes. The aim of this narrative review is to investigate the role of blood pressure (BP) monitoring, physical activity, and prophylactic aspirin to reduce the prevalence of preeclampsia and to improve pregnancy outcome in women with preexisting diabetes. Home BP and office BP in early pregnancy are positively associated with development of preeclampsia, and home BP and office BP are comparable for the prediction of preeclampsia in women with preexisting diabetes. However, home BP is lower than office BP, and the difference is greater with increasing office BP. Daily physical activity is recommended during pregnancy, and limiting sedentary behavior may be beneficial to prevent preeclampsia. White coat hypertension in early pregnancy is not a clinically benign condition but is associated with an elevated risk of developing preeclampsia. This renders the current strategy of leaving white coat hypertension untreated debatable. A beneficial preventive effect of initiating low-dose aspirin (150 mg/day) for all in early pregnancy has not been demonstrated in women with preexisting diabetes.

Management of type 2 diabetes in pregnancy: a narrative review

The prevalence of type 2 diabetes (T2DM) at reproductive age is rising. Women with T2DM have a similarly high risk for pregnancy complications as pregnant women with type 1 diabetes. To reduce adverse pregnancy and neonatal outcomes, such as preeclampsia and preterm delivery, a multi-target approach is necessary. Tight glycemic control together with appropriate gestational weight gain, lifestyle measures, and if necessary, antihypertensive treatment and low-dose aspirin is advised. This narrative review discusses the latest evidence on preconception care, management of diabetes-related complications, lifestyle counselling, recommendations on gestational weight gain, pharmacologic treatment and early postpartum management of T2DM.

Management of type 1 diabetes in pregnancy: update on lifestyle, pharmacological treatment, and novel technologies for achieving glycaemic targets

Glucose concentrations within target, appropriate gestational weight gain, adequate lifestyle, and, if necessary, antihypertensive treatment and low-dose aspirin reduces the risk of pre-eclampsia, preterm delivery, and other adverse pregnancy and neonatal outcomes in pregnancies complicated by type 1 diabetes. Despite the increasing use of diabetes technology (ie, continuous glucose monitoring and insulin pumps), the target of more than 70% time in range in pregnancy (TIRp 3·5-7·8 mmol/L) is often reached only in the final weeks of pregnancy, which is too late for beneficial effects on pregnancy outcomes. Hybrid closed-loop (HCL) insulin delivery systems are emerging as promising treatment options in pregnancy. In this Review, we discuss the latest evidence on pre-pregnancy care, management of diabetes-related complications, lifestyle recommendations, gestational weight gain, antihypertensive treatment, aspirin prophylaxis, and the use of novel technologies for achieving and maintaining glycaemic targets during pregnancy in women with type 1 diabetes. In addition, the importance of effective clinical and psychosocial support for pregnant women with type 1 diabetes is also highlighted. We also discuss the contemporary studies examining HCL systems in type 1 diabetes during pregnancies.

Hypertensive disorders of pregnancy pre- and postaspirin guideline publication in individuals with pregestational diabetes mellitus

BACKGROUND

The US Preventive Services Taskforce published guidelines in 2014 recommending that low-dose aspirin be initiated between 12 and 28 weeks of gestation among high-risk patients for preeclampsia prophylaxis. Moreover, low-dose aspirin is recommended by some clinicians for the prevention of preterm birth.

OBJECTIVE

This study aimed to evaluate whether there is an association between the US Preventive Services Taskforce aspirin guideline hypertensive disorders of pregnancy and the rates of hypertensive disorders of pregnancy and preterm birth in individuals with pregestational diabetes mellitus.

STUDY DESIGN

This was a repeated cross-sectional analysis of individuals with pregestational diabetes mellitus and at least 1 singleton delivery at >20 weeks of gestation with records available in the National Vital Statistics System between 2010 and 2018. The primary outcome was hypertensive disorders of pregnancy, and the secondary outcome was preterm birth. Demographics and clinical characteristics among individuals in the pre-US Preventive Services Taskforce guideline cohort (2010-2013) were compared with that of individuals in the post-US Preventive Services Taskforce guideline cohort (2015-2018). Multivariable regression estimated the odds ratios and 95% confidence intervals for the association between guideline publication and the selected endpoints. Effect modification was assessed for access to prenatal care using the Kotelchuck Index (<80% vs ≥80%). Furthermore, a sensitivity analysis limited to nulliparas was performed.

RESULTS

Overall, 224,065 individuals were included. Individuals in the post-US Preventive Services Taskforce guideline cohort were more likely to be older, be obese, and have a history of preterm birth. In unadjusted and adjusted modeling, delivery in the post-US Preventive Services Taskforce guideline cohort was associated with hypertensive disorders of pregnancy (adjusted odds ratio, 1.25; 95% confidence interval, 1.22-1.28) and preterm birth (adjusted odds ratio, 1.10; 95% confidence interval, 1.08-1.12). The adjusted odds ratios for hypertensive disorders of pregnancy and preterm birth were more pronounced among those with less than adequate access to care. The findings were similar in the sensitivity analysis of only nulliparas.

CONCLUSION

Delivery after US Preventive Services Taskforce aspirin guideline publication was associated with higher rates of hypertensive disorders of pregnancy and preterm birth in a population of individuals with diabetes mellitus. It is unknown whether patient or practitioner factors, or other changes in obstetrical care, contributed to these findings.

Aspirin and Pravastatin for Preeclampsia Prevention in High-Risk Pregnancy

Preeclampsia is a hypertensive disorder of pregnancy affecting up to 8% of pregnancies. It is associated with significant neonatal and maternal morbidities and mortality. Although its pathogenesis is not completely understood, abnormal placentation resulting in imbalance in angiogenic factors, increased inflammation, and endothelial dysfunction are thought to be key pathways in the development of the disease. Administration of low-dose aspirin is recommended by professional societies for the prevention of preeclampsia in high-risk individuals. In this review, we summarize the evidence behind the use of low-dose aspirin and pravastatin in pregnant individuals at high risk of preeclampsia.

Aspirin 75 mg to prevent preeclampsia in high-risk pregnancies: a retrospective real-world study in China

BACKGROUND

Several randomized clinical trials showed that aspirin could decrease the incidence of preeclampsia (PE) in women at high risk, but data from sources other than traditional clinical trials that investigating the preventive effect of aspirin 75 mg on PE is still lacking, especially in mainland China. We aimed to use Chinese real-world data to estimate the preventive effect of low-dose aspirin (LDA) on PE.

METHODS

Clinical data of pregnant women who were at high risk of PE and had their first prenatal visit at the affiliated Taicang People's Hospital of Soochow University during November 31, 2018 and May 10, 2021 was retrospectively analyzed. Among the 266 included pregnant women, 115 individuals treated with aspirin 75 mg per day and the other 151 without such treatment were considered as the LDA group and the control group, respectively.

RESULTS

In the LDA group, 64 (55.65%) of 115 pregnant women took aspirin before 16 weeks of gestation. Besides, 12 (10.43%) and 34 (22.52%) women developed PE in the LDA group and control group, respectively; the aspirin prophylaxis was associated with a lower risk of PE (odds ratio = 0.40, 95% confidence interval = 0.20-0.82, P = 0.0098). In addition, LDA is slightly more effective when initiated before 16 weeks of gestation or in those without chronic hypertension, when compared with their counterparts.

CONCLUSION

Prophylaxis with 75 mg per day of aspirin in high-risk women resulted in a significantly lower incidence of PE than that in the control group.

Aspirin for prevention of preeclampsia and adverse perinatal outcome in twin pregnancies: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the potential role of aspirin in reducing the risk of preeclampsia and adverse maternal and perinatal outcomes in twin pregnancies.

DATA SOURCES

Medline, Embase, Google Scholar, Cochrane, and ClinicalTrial.gov databases were searched.

STUDY ELIGIBILITY CRITERIA

The search and selection criteria were restricted to the English language.

METHODS

The primary outcome was the incidence of preeclampsia. The secondary outcomes included gestational hypertension; fetal growth restriction; preterm birth, either spontaneous or iatrogenic, before 34 weeks of gestation; gestational age at birth; neonatal birthweight; and adverse events secondary to the administration of aspirin, including antepartum and postpartum hemorrhage. In addition, subgroup analyses according to chorionicity (dichorionic vs monochorionic), aspirin dose, and gestational age at administration of aspirin (<16 vs ≥16 weeks of gestation) and considering only studies with a daily aspirin dose of ≥100 mg/d were performed. Head-to-head meta-analyses reporting results as summary odds ratios and mean differences were used to analyze categorical and continuous variables, respectively. Quality assessment for randomized controlled trials was independently performed by 2 researchers based on the risk of bias that was assessed using the revised Cochrane risk-of-bias tool for randomized trials. The conclusion of the meta-analysis on the primary outcome was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

Overall, 9 studies (2273 twin pregnancies) were included. When considering all studies, the risk of preeclampsia was lower in twin pregnancies treated with aspirin than in those not treated with aspirin (odds ratio, 0.64; 95% confidence interval, 0.48-0.85; P=.003), although there was no significant difference in the risk of gestational hypertension (P=.987), fetal growth restriction (P=.9), or adverse maternal and perinatal events (P=.9) in twin pregnancies treated with aspirin compared with those not treated with aspirin. There was no significant difference in the gestational age at birth (P=.2) and neonatal birthweight (P=.06) between women receiving aspirin and those not receiving aspirin. When considering only studies with an aspirin dose of >100 mg/d, the risk of preeclampsia (odds ratio, 0.45; 95% confidence interval, 0.23-0.86; P=.02) was significantly lower in pregnancies receiving aspirin than in those not receiving aspirin, Conversely, there was no significant difference in the risk of gestational hypertension (P=.20), fetal growth restriction (P=.1), gestational age at birth (P=.06), and neonatal weight (P=.05) between the 2 groups. Furthermore, there was no significant difference in the risk of preeclampsia when considering only studies with an aspirin dose of >80 mg/d (P=.611). The association between the administration of aspirin and preeclampsia persisted when considering an aspirin dose of >100 mg/day or when the medication was started before 16 weeks of gestation. The overall quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation assessment was low.

CONCLUSION

The administration of aspirin in women with twin pregnancies reduced the risk of preeclampsia. The findings from this study highlighted the need for randomized controlled trials elucidating the actual role of aspirin in affecting maternal and perinatal outcomes in twin pregnancies.

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

OBJECTIVE

The association between aspirin use during pregnancy and the risk of postpartum hemorrhage remains unclear. This study aimed to explore the incidence of postpartum hemorrhage and the amount of postpartum blood loss among women who used aspirin during pregnancy.

DATA SOURCES

From inception to October 2022, this study searched the following databases: MEDLINE, Web of Science, Embase, and the Cochrane Central Register of Controlled Trials.

STUDY ELIGIBILITY CRITERIA

Studies comparing pregnancy outcomes that covered the incidence of postpartum hemorrhage or the amount of postpartum blood loss in pregnancies with aspirin vs placebo (or no aspirin) were included.

METHODS

Reviewers separately ascertained studies, obtained data, and gauged study quality. The meta-analysis was conducted using a random effects model owing to the probable heterogeneity of the included studies. The rates of postpartum hemorrhage or the mean amounts of postpartum blood loss were compared, and the odds ratios or mean differences with 95% confidence intervals were estimated. Of note, 2 parts performed both a pooled analysis of randomized controlled trials and cohort studies and a separate analysis of randomized controlled trials.

RESULTS

Overall, 21 studies with 373,926 women were included in the postpartum hemorrhage part, and 7 studies with 10,163 women were included in the postpartum blood loss part. The results suggested that aspirin use during pregnancy was associated with an increased incidence of postpartum hemorrhage (odds ratio, 1.20; 95% confidence interval, 1.07-1.34). When only randomized controlled trials were retained, the results remained significant (odds ratio, 1.12; 95% confidence interval, 1.00-1.25). In the second part, higher total blood loss after delivery was obtained (mean difference, 12.85 mL; 95% confidence interval, 3.28-22.42), and the result was unaltered when cohort studies were eliminated (mean difference, 13.72 mL; 95% confidence interval, 4.63-22.81). The conclusions are more likely to be obtained in developed countries.

CONCLUSION

Aspirin use during pregnancy is a potential risk of postpartum hemorrhage and does slightly increase the amount of postpartum blood loss. Without denying the combined value of aspirin, our conclusions raised an alarm for clinicians about postpartum hemorrhage in women using aspirin during pregnancy.

Redefining the Roles of Aspirin across the Spectrum of Cardiovascular Disease Prevention

Even before its role in platelet inhibition was fully characterized in the 1980s, aspirin had been incorporated into the cardiovascular disease care algorithm. Early trials examining its use in unstable angina and acute myocardial infarction revealed evidence of its protective role in the secondary prevention of atherosclerotic cardiovascular disease (ASCVD). Large trials assessing use in the primary prevention setting and optimal dosing regimens were studied in the late 1990s and early 2000s. As a cornerstone of cardiovascular care, aspirin was incorporated into primary and secondary ASCVD prevention guidelines in the United States and mechanical heart valve guidelines. However, in recent years, with significant advances in medical and interventional ASCVD therapies, scrutiny has been placed on the bleeding profile of aspirin, and guidelines have adapted to new evidence. Updates in primary prevention guidelines reserve aspirin only for patients at higher ASCVD risk and low bleeding risk - though questions remain in ASCVD risk assessment as risk-enhancing factors have proven difficult to incorporate on a population level. New thoughts regarding aspirin use in secondary prevention - especially with the concomitant use of anticoagulants - have altered recommendations as additional data accrued. Finally, a recommendation for aspirin and vitamin K antagonists with mechanical heart valves has been modified. Despite aspirin losing a foothold in cardiovascular care, new evidence has strengthened claims for its use in women at high risk for preeclampsia.

Effects of race and ethnicity on perinatal outcomes in high-income and upper-middle-income countries: an individual participant data meta-analysis of 2 198 655 pregnancies

BACKGROUND

Existing evidence on the effects of race and ethnicity on pregnancy outcomes is restricted to individual studies done within specific countries and health systems. We aimed to assess the impact of race and ethnicity on perinatal outcomes in high-income and upper-middle-income countries, and to ascertain whether the magnitude of disparities, if any, varied across geographical regions.

METHODS

For this individual participant data (IPD) meta-analysis we used data from the International Prediction of Pregnancy Complications (IPPIC) Network of studies on pregnancy complications; the full dataset comprised 94 studies, 53 countries, and 4 539 640 pregnancies. We included studies that reported perinatal outcomes (neonatal death, stillbirth, preterm birth, and small-for-gestational-age babies) in at least two racial or ethnic groups (White, Black, south Asian, Hispanic, or other). For our two-step random-effects IPD meta-analysis, we did multiple imputations for confounder variables (maternal age, BMI, parity, and level of maternal education) selected with a directed acyclic graph. The primary outcomes were neonatal mortality and stillbirth. Secondary outcomes were preterm birth and a small-for-gestational-age baby. We estimated the association of race and ethnicity with perinatal outcomes using a multivariate logistic regression model and reported this association with odds ratios (ORs) and 95% CIs. We also did a subgroup analysis of studies by geographical region.

FINDINGS

51 studies from 20 high-income and upper-middle-income countries, comprising 2 198 655 pregnancies, were eligible for inclusion in this IPD meta-analysis. Neonatal death was twice as likely in babies born to Black women than in babies born to White women (OR 2·00, 95% CI 1·44-2·78), as was stillbirth (2·16, 1·46-3·19), and babies born to Black women were at increased risk of preterm birth (1·65, 1·46-1·88) and being small for gestational age (1·39, 1·13-1·72). Babies of women categorised as Hispanic had a three-times increased risk of neonatal death (OR 3·34, 95% CI 2·77-4·02) than did those born to White women, and those born to south Asian women were at increased risk of preterm birth (OR 1·26, 95% CI 1·07-1·48) and being small for gestational age (1·61, 1·32-1·95). The effects of race and ethnicity on preterm birth and small-for-gestational-age babies did not vary across regions.

INTERPRETATION

Globally, among underserved groups, babies born to Black women had consistently poorer perinatal outcomes than White women after adjusting for maternal characteristics, although the risks varied for other groups. The effects of race and ethnicity on adverse perinatal outcomes did not vary by region.

FUNDING

National Institute for Health and Care Research, Wellbeing of Women.

Aspirin for the prevention of preeclampsia: A systematic review and meta-analysis of randomized controlled studies

BACKGROUND

The results of randomized controlled studies on aspirin for the prevention of preeclampsia (PE) are conflicting, and some of the related meta-analyses also have limitations or flaws.

DATA SOURCES

A search was conducted on PubMed, Embase, and Cochrane Central Register of Controlled Trials databases, with no time or language restrictions.

STUDY ELIGIBILITY CRITERIA

Randomized controlled studies comparing aspirin for the prevention of PE were conducted.

METHODS

Systematic reviews were performed according to the Cochrane Manual guidelines. A fixed-effects model or a random-effects model was chosen to calculate pooled relative risks with 95% confidence intervals based on the heterogeneity of the included studies. The study aimed to investigate the effect of aspirin on the development of PE in high-risk and general populations of women. Publication bias was assessed by funnel plots. All included studies were assessed for bias by the Cochrane Manual of Bias Assessment. Subgroup analyses were conducted on the aspirin dose, time of initial aspirin intervention, and the region in which the research was conducted, to explore the effective dose of aspirin and time of initial aspirin intervention and to try to find sources of heterogeneity and publication bias.

RESULTS

A total of 39 articles were included, including 29 studies involving pregnant women at high risk for PE (20,133 patients) and 10 studies involving a general population of pregnant women (18,911 patients). Aspirin reduced the incidence of PE by 28% (RR 0.72, 95% CI 0.62-0.83) in women at high risk for PE. Aspirin reduced the incidence of PE by 30% in the general population (RR 0.70, 95% CI 0.52-0.95), but sensitivity analyses found that aspirin in the general population was not robust. A subgroup analysis showed that an aspirin dose of 75 mg/day (RR 0.50, 95% CI 0.32-0.78) had a better protective effect than other doses. Starting aspirin at 12-16 weeks (RR 0.62, 95% CI 0.53-0.74) of gestation or 17-28 weeks (RR 0.62, 95% CI 0.44-0.89) reduced the incidence of PE by 38% in women at high risk for PE, but the results were more reliable for use at 12-16 weeks. Heterogeneity and publication bias of the included studies may be mainly due to the studies completed in Asia.

CONCLUSION

Aspirin is recommended to be started at 12-16 weeks of pregnancy in women at high risk for PE. The optimal dose of aspirin to use is 75 mg/d.

SYSTEMATIC REVIEW REGISTRATION

[www.ClinicalTrials.gov], identifier [CRD42022319984].

Regulation of Placental Efflux Transporters during Pregnancy Complications

The placenta is essential for regulating the exchange of solutes between the maternal and fetal circulations. As a result, the placenta offers support and protection to the developing fetus by delivering crucial nutrients and removing waste and xenobiotics. ATP-binding cassette transporters, including multidrug resistance protein 1, multidrug resistance-associated proteins, and breast cancer resistance protein, remove chemicals through active efflux and are considered the primary transporters within the placental barrier. Altered transporter expression at the barrier could result in fetal exposure to chemicals and/or accumulation of xenobiotics within trophoblasts. Emerging data demonstrate that expression of these transporters is changed in women with pregnancy complications, suggesting potentially compromised integrity of placental barrier function. The purpose of this review is to summarize the regulation of placental efflux transporters during medical complications of pregnancy, including 1) placental inflammation/infection and chorioamnionitis, 2) hypertensive disorders of pregnancy, 3) metabolic disorders including gestational diabetes and obesity, and 4) fetal growth restriction/altered fetal size for gestational age. For each disorder, we review the basic pathophysiology and consider impacts on the expression and function of placental efflux transporters. Mechanisms of transporter dysregulation and implications for fetal drug and toxicant exposure are discussed. Understanding how transporters are up- or downregulated during pathology is important in assessing possible exposures of the fetus to potentially harmful chemicals in the environment as well as the disposition of novel therapeutics intended to treat placental and fetal diseases. SIGNIFICANCE STATEMENT: Diseases of pregnancy are associated with reduced expression of placental barrier transporters that may impact fetal pharmacotherapy and exposure to dietary and environmental toxicants.

Medications for preventing hypertensive disorders in high-risk pregnant women: a systematic review and network meta-analysis

OBJECTIVES

To determine the relative effectiveness of medications for preventing hypertensive disorders in high-risk pregnant women and to provide a ranking of medications using network meta-analysis.

METHODS

All randomized controlled trials comparing the most commonly used medications to prevent hypertensive disorders in high-risk pregnant women that are nulliparity and pregnant women having family history of preeclampsia, history of pregnancy-induced hypertension in previous pregnancy, obstetric risks, or underlying medical diseases. We received the search results from the Cochrane Pregnancy and Childbirth's Specialised Register of Controlled Trials, searched on 31st July 2020. At least two review authors independently selected the included studies and extracted the data and the methodological quality. The comparative risk ratios (RR) and 95% confidence intervals (CI) were analyzed using pairwise and network meta-analyses, and treatment rankings were estimated by the surface under the cumulative ranking curve for preventing preeclampsia (PE), gestational hypertension (GHT), and superimposed preeclampsia (SPE). Safety of the medications is also important for decision-making along with effectiveness which will be reported in a separate review.

RESULTS

This network meta-analysis included 83 randomized studies, involving 93,864 women across global regions. Three medications, either alone or in combination, probably prevented PE in high-risk pregnant women when compared with a placebo or no treatment from network analysis: antiplatelet agents with calcium (RR 0.19, 95% CI 0.04 to 0.86; 1 study; low-quality evidence), calcium (RR 0.61, 95% CI 0.47 to 0.80; 13 studies; moderate-quality evidence), antiplatelet agents (RR 0.69, 95% CI 0.57 to 0.82; 31 studies; moderate-quality evidence), and antioxidants (RR 0.77, 95% CI 0.63 to 0.93; 25 studies; moderate-quality evidence). Calcium probably prevented PE (RR 0.63, 95% CI 0.46 to 0.86; 11 studies; moderate-quality evidence) and GHT (RR 0.89, 95% CI 0.84 to 0.95; 8 studies; high-quality evidence) in nulliparous/primigravida women. Few included studies for the outcome of superimposed preeclampsia were found.

CONCLUSION

Antiplatelet agents, calcium, and their combinations were most effective medications for preventing hypertensive disorders in high-risk pregnant women when compared with a placebo or no treatment. Any high-risk characteristics for women are important in deciding the best medications. The qualities of evidence were mostly rated to be moderate.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018096276.

The association between chronic liver diseases and preeclampsia

Background

Preeclampsia is a multisystem disorder characterized by an abnormal vascular response to placentation associated with increased systemic vascular resistance. As liver involvement is one of the main clinical features of preeclampsia, we sought to determine if there is an association between chronic liver diseases and preeclampsia.

Methods

A retrospective matched case–control analysis was conducted in a tertiary medical center. Three hundred eleven (311) pregnant women with preexisting chronic liver disease (study group), including viral and autoimmune hepatitis, non-alcoholic fatty liver, Wilson disease, and cirrhosis, were match for age, parity, and number of fetuses to 933 healthy pregnant women (control group). The primary outcome measure was the incidence of preeclampsia in each group. Secondary outcome measures were obstetrical and neonatal complications. Confounders found to be significant on univariate analysis were evaluated using logistic regression models, and odds ratios (OR) and confidence intervals (CI) were calculated.

Results

Preeclampsia was diagnosed in 28 women (9.0%) in the study group and 33 women (3.54%) in the control group (p < 0.001).

On multivariate analysis adjusted for maternal age, parity, previous preeclampsia, chronic hypertension, gestational diabetes mellitus, pregestational diabetes mellitus, antiphospholipid syndrome, and mode of conception, chronic liver disease was found to be an independent risk factor for preeclampsia (aOR 2.631, 95% CI 1.518–4.561). Although there was no difference in the gestational week at delivery between the groups (38.6 ± 2.13 vs. 38.8 ± 2.17 for study and control group, respectively, p = 0.410), the study group had a lower mean neonatal birthweight (3088 ± 551 vs. 3182 ± 566 g, p = 0.011). There were no between-group differences in the other parameters evaluated.

Conclusion

In our study, preexisting chronic liver disease was associated with a 2.6-fold increased risk of preeclampsia.

Prevention of Coronary Artery Disease in Women

PURPOSE OF REVIEW

Cardiovascular disease remains the leading cause of morbidity and mortality in women. Women were historically underrepresented in landmark trials for which cardiovascular guidelines are based on and are prone to gender-specific risk factors that predispose to coronary heart disease.

RECENT FINDINGS

More attention has been made on gender and pregnancy-associated risk factors such as autoimmune disorders and preeclampsia. The most recent guidelines have reflected the need to consider risk-enhancing factors that are unaccounted for in traditional risk assessment tools. As the population ages and the burden of cardiovascular disease in women increases, it is crucial to continue focusing on preventative of cardiovascular disease in 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.

The role of aspirin dose and initiation time in the prevention of preeclampsia and corresponding complications: a meta-analysis of RCTs

PURPOSE

To investigate the role of different dosages and initial times of aspirin in preeclampsia prevention.

METHODS

This meta-analysis was performed based on randomized-control trials (RCTs). RCTs of women assigned to receive low-dose aspirin, placebo, or no treatment were included. Preeclampsia and corresponding complications were pooled for analysis. All studies were retrieved from PubMed, Embase, Cochrane and Web of Science.

RESULTS

A total of 46 studies were obtained in this meta-analysis, which consisted of 24,028 participants. When women at ≤ 16 gestational weeks started treatment with a dosage of < 100 mg/day aspirin, there was a significant reduction in the incidence of preeclampsia (RR = 0.75; 95% CI 0.58-0.98; P = 0.03), while in the subgroup receiving ≥ 100 mg/day aspirin, the result was RR = 0.71 (95% CI 0.53-0.95; P = 0.02). When aspirin was initiated at > 16 weeks, with a dosage of < 100 mg/day aspirin, there was a lesser preventive effect (RR = 0.80; 95% Cl 0.64-1.00; P = 0.05), and there was no significance in the subgroup receiving ≥ 100 mg/day aspirin (RR = 0.76; 95% Cl 0.45-1.31;  P =  0.32). Furthermore, aspirin was revealed to have a protective effect on reducing preterm delivery, but there was an increased risk of postpartum hemorrhage. No significant result was obtained for fetal loss.

CONCLUSION

The results of this meta-analysis suggest that high-risk pregnant women can prevent preeclampsia or preterm delivery by taking low-dose aspirin; the most efficient period is ≤ 16 weeks of gestation, and the best dose is ≥ 100 mg.

Pre-Eclampsia Biomarkers for Women With Type 1 Diabetes Mellitus: A Comprehensive Review of Recent Literature

Background: Pre-eclampsia is a serious consideration for women with type 1 diabetes mellitus (T1DM) planning pregnancy. Risk stratification strategies, such as biomarkers measured in the first trimester of pregnancy, could help identify high-risk women. The literature on T1DM-specific pre-eclampsia biomarkers is expanding. We aimed to provide a narrative review of recently published evidence to identify the most promising biomarker candidates that could be targeted for clinical implementation in existing PE models. Methods: A search using MeSH terms was carried out of Medline, EMBASE, Maternity and Infant Care, Web of Science, and Scopus for relevant papers published since 2015 inclusive and in English. The time limit was applied from the publication of the preceding systematic review in this field. Included studies had pre-eclampsia as a primary outcome, measured one or more serum, plasma or urine biomarkers at any time during pregnancy, and had a distinct group of women with T1DM who developed pre-eclampsia. Studies with pre-eclampsia as a composite outcome were not considered. No restrictions on study types were applied. A narrative synthesis approach was adopted for analysis. Results: A total of 510 records were screened yielding 18 eligible studies relating to 32 different biomarkers. Higher first-trimester levels of HbA1c and urinary albumin were associated with an increased risk of pre-eclampsia development in women with T1DM. Urinary neutrophil gelatinase-associated lipocalin and adipokines were novel biomarkers showing moderate predictive ability before 15 gestational weeks. Two T1DM-specific pre-eclampsia prediction models were proposed, measuring adipokines or urinary neutrophil gelatinase-associated lipocalin together with easily attainable maternal clinical characteristics. Contradicting previous literature, pre-eclampsia risk in women with T1DM was correlated with vitamin D levels and atherogenic lipid profile in the context of haptoglobin phenotype 2-2. Pregnancy-associated plasma protein-A and soluble endoglin did not predict pre-eclampsia in women with T1DM, and soluble Fms-like tyrosine kinase 1 only predicted pre-eclampsia from the third trimester. Conclusion: Maternally derived biomarkers reflecting glycemic control, insulin resistance and renal dysfunction performed better as PE predictors among women with T1DM than those derived from the placenta. These biomarkers could be trialed in current PE prediction algorithms to tailor them for women with T1DM.

[Use of aspirin 100 mg / day to prevent Preeclampsia, in high risk pregnancies, in a cohort from Argentina]

Objectives

The objective of the present study was to analyse the use of 100 g aspirin dose as prevention method for preeclampsia in high risk pregnant patients.

Methods

A retrospective cohort study was performed in high risk pregnant patients with a blood pressure protocol, and the use of 100 mg of aspirin vs. its non-use was evaluated in the incidence of PREEC. Estimations between the two groups were performed with and without variable adjustment by means of binary logistic regression models.

Results

633 high risk pregnant patients were evaluated. The average age was 30±7 years old, and 25±8 weeks of pregnancy. 281 women (44.3 %) within this group received aspirin. The total prevalence of PREEC in our sample was 151 pregnant women (23.8 %). Pregnant patients under the aspirin treatment developed less PREEC events (19.2% vs 27.5%, p=0.019); with OR not adjusted 0.62 (IC95% 0.43-0.91 p= 0.017). The risk was similar when it was adjusted by age, preeclampsia history, diabetes mellitus and chronic high blood pressure. (OR adjusted 0.63 IC95% 0.43-0.92 p= 0.017).

Conclusions

The use of 100 mg of aspirin a day before the 20th week of pregnancy in high risk pregnant patients decreased the risk of developing PREEC, regardless the age and risk factors.

Glycemic Control and Aspirin Resistance in Patients Taking Low-Dose Aspirin for Pre-eclampsia Prevention

OBJECTIVES

To assess the association between aspirin and glycemic control in diabetic, pregnant patients, and the risk for aspirin resistance in those with poor glycemic control across gestation taking low-dose aspirin (LDA) for pre-eclampsia (PEC) prevention.

STUDY DESIGN

We performed a secondary analysis of samples collected during the Maternal-Fetal Medicine Units trial of LDA for PEC prevention. A subset of insulin-controlled diabetic patient samples on placebo or 60 mg aspirin daily were evaluated. Glycosylated hemoglobin was measured at randomization, mid-second trimester, and third trimester time points. Thromboxane B₂ (TXB₂) measurements were previously assessed as part of the original study. Primary outcome was the effect of LDA on glycosylated hemoglobin levels compared with placebo across gestation.

RESULTS

Levels of glycosylated hemoglobin increased across gestation in the placebo group (2,067.7 [interquartile range, IQR: 1,624.6-2,713.5 µg/mL] vs. 2,461.9 [1,767.0-3,209.9 µg/mL] vs. 3,244.3 [2,691.5-4,187.0 µg/mL]; p < 0.01) compared with no difference in levels of glycosylated hemoglobin across gestation in the LDA group (2,186.4 [IQR: 1,462.3-3,097.7 µg/mL] vs. 2,337.1 [1,327.7-5,932.6 µg/mL] vs. 2,532.9 [1,804.9-5,511.8 µg/mL]; p = 0.78). Higher levels of glycosylated hemoglobin were associated with increased TXB₂ levels prior to randomization (r = 0.67, p < 0.05). Incomplete TXB₂ was higher in pregnancies with increasing levels of glycosylated hemoglobin compared with those with decreasing levels of glycosylated hemoglobin across gestation (69.2 vs. 18.1%, p = 0.02).

CONCLUSION

LDA exposure may be beneficial to glycemic control in this patient population. Additionally, poor glycemic control is associated with a higher level of TXB₂ in diabetic pregnant patients on LDA. Higher doses of aspirin may be required in these patients to prevent development of PEC.

KEY POINTS

· Low-dose aspirin may improve glycemic control.. · Poor glycemic control increases risk for aspirin resistance.. · Higher doses of aspirin may be required for pre-eclampsia prevention..

The prediction of preeclampsia: the way forward

Despite intensive investigation, we still cannot adequately predict, treat, or prevent preeclampsia. We have gained awareness that preeclampsia is a syndrome not a disease and is heterogeneous in its presentation and pathophysiology, which may indicate differing underlying phenotypes, and that the impact extends beyond pregnancy per se. Effects on the fetus and mother extend many years after pregnancy, as evidenced by fetal programming of adult disease and increased risk of the development of maternal cardiovascular disease. The increased occurrence of preeclampsia in women with preexisting risk factors suggests that the stress of pregnancy may expose subclinical vascular disease as opposed to preeclampsia damaging the vasculature. The heterogeneity of preeclampsia has blighted efforts to predict preeclampsia early in gestation and has thwarted success in attempts at therapy with treatments, such as low-dose aspirin or global antioxidants. There is a critical need to identify the phenotypes to enable their specific prediction and treatment. Such studies require considerably larger collections of patients than employed in past and current studies. This does not necessarily imply much larger patient numbers in single studies but can be facilitated by the ability to easily combine many smaller studies. This can be accomplished by agreeing on a priori standardized and harmonized clinical data and biospecimen collection across new studies. Such standards are being established by international groups of investigators. Leadership by international organizations, perhaps adopting a carrot and stick approach, to overcome investigator, institutional and funder reticence toward data sharing is required to ensure adoption of such standards. Future studies should include women in both low- and high-resource settings and employ social media and novel methods for data collection and analysis, including machine learning and artificial intelligence. The goal is to identify the pathophysiology underlying differing preeclampsia phenotypes, their successful prediction with the design, and the implementation of phenotype-specific therapies.

Proteinuria during pregnancy: definition, pathophysiology, methodology, and clinical significance

Qualitative and quantitative measurement of urine protein excretion is one of the most common tests performed during pregnancy. For more than 100 years, proteinuria was necessary for the diagnosis of preeclampsia, but recent guidelines recommend that proteinuria is sufficient but not necessary for the diagnosis. Still, in clinical practice, most patients with gestational hypertension will be diagnosed as having preeclampsia based on the presence of proteinuria. Although the reference standard for measuring urinary protein excretion is a 24-hour urine collection, spot urine protein-to-creatinine ratio is a reasonable "rule-out" test for proteinuria. Urine dipstick screening for proteinuria does not provide any clinical benefit and should not be used to diagnose proteinuria. The classic cutoff cited to define proteinuria during pregnancy is a value of >300 mg/24 hours or a urine protein-to-creatinine ratio of at least 0.3. Using this cutoff, the rate of isolated proteinuria in pregnancy may reach 8%, whereas preeclampsia occurs among 3% to 8% of pregnancies. Although this threshold is widely accepted, its origin is not based on evidence on adverse pregnancy outcomes but rather on expert opinion and results of small studies. After reviewing the available data, the most important factor that influences maternal and neonatal outcome is the severity of blood pressures and presence of end organ damage, rather than the excess protein excretion. Because the management of gestational hypertension and preeclampsia without severe features is almost identical in frequency of surveillance and timing of delivery, the separation into 2 disorders is unnecessary. If the management of women with gestational hypertension with a positive assessment of proteinuria will not change, we believe that urine assessment for proteinuria is unnecessary in women who develop new-onset blood pressure at or after 20 weeks' gestation. Furthermore, we do not recommend repeated measurement of proteinuria for women with preeclampsia, the amount of proteinuria does not seem to be related to poor maternal and neonatal outcomes, and monitoring proteinuria may lead to unindicated preterm deliveries and related neonatal complications. Our current diagnosis of preeclampsia in women with chronic kidney disease may be based on a change in protein excretion, a baseline protein excretion evaluation is critical in certain conditions such as chronic hypertension, diabetes, and autoimmune or other renal disorders. The current definition of superimposed preeclampsia possesses a diagnostic dilemma, and it is unclear whether a change in the baseline proteinuria reflects another systemic disease such as preeclampsia or whether women with chronic disease such as chronic hypertension or diabetes will experience a different "normal" pattern of protein excretion during pregnancy. Finally, limited data are available regarding angiogenic and other biomarkers in women with chronic kidney disease as a potential aid in distinguishing the worsening of baseline chronic kidney disease and chronic hypertension from superimposed preeclampsia.

A randomized controlled trial of low-dose aspirin for the prevention of preeclampsia in women at high risk in China

BACKGROUND

Low-dose aspirin has been the most widely studied preventive drug for preeclampsia. However, guidelines differ considerably from country to country regarding the prophylactic use of aspirin for preeclampsia. There is limited evidence from large trials to determine the effect of 100 mg of aspirin for preeclampsia screening in women with high-risk pregnancies, based on maternal risk factors, and to guide the use of low-dose aspirin in preeclampsia prevention in China.

OBJECTIVE

The Low-Dose Aspirin in the Prevention of Preeclampsia in China study was designed to evaluate the effect of 100 mg of aspirin in preventing preeclampsia among high-risk pregnant women screened with maternal risk factors in China, where preeclampsia is highly prevalent, and the status of low-dose aspirin supply is commonly suboptimal.

STUDY DESIGN

We conducted a multicenter randomized controlled trial at 13 tertiary hospitals from 11 provinces in China between 2016 and 2019. We assumed that the relative reduction in the incidence of preeclampsia was at least 20%, from 20% in the control group to 16% in the aspirin group. Therefore, the targeted recruitment number was 1000 participants. Women were randomly assigned to the aspirin or control group in a 1:1 allocation ratio. Statistical analyses were performed according to an intention-to-treat basis. The primary outcome was the incidence of preeclampsia, diagnosed along with a systolic blood pressure of ≥140 mm Hg or a diastolic blood pressure of ≥90 mm Hg after 20 weeks of gestation, with a previously normal blood pressure (systolic blood pressure of <140 mm Hg and diastolic blood pressure of <90 mm Hg), and complicated by proteinuria. The secondary outcomes included maternal and neonatal outcomes. Logistic regression analysis was used to determine the significance of difference of preeclampsia incidence between the groups for both the primary and secondary outcomes. Interaction analysis was also performed.

RESULTS

A total of 1000 eligible women were recruited between December 2016 and March 2019, of which the final 898 patients were analyzed (464 participants in the aspirin group, 434 participants in the control group) on an intention-to-treat basis. No significant difference was found in preeclampsia incidence between the aspirin group (16.8% [78/464]) and the control group (17.1% [74/434]; relative risk, 0.986; 95% confidence interval, 0.738-1.317; P=.924). Likewise, adverse maternal and neonatal outcomes did not differ significantly between the 2 groups. Meanwhile, the incidence of postpartum hemorrhage between the 2 groups was similar (6.5% [30/464] in the aspirin group and 5.3% [23/434] in the control group; relative risk, 1.220; 95% confidence interval, 0.720-2.066; P=.459). We did not find any significant differences in preeclampsia incidence between the 2 groups in the subgroup analysis of the different risk factors.

CONCLUSION

A dosage of 100 mg of aspirin per day, initiated from 12 to 20 gestational weeks until 34 weeks of gestation, did not reduce the incidence of preeclampsia in pregnant women with high-risk factors in China.

Toward personalized management of chronic hypertension in pregnancy

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

Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

Prediction of preeclampsia throughout gestation with maternal characteristics and biophysical and biochemical markers: a longitudinal study

BACKGROUND

The current approach to predict preeclampsia combines maternal risk factors and evidence from biophysical markers (mean arterial pressure, Doppler velocimetry of the uterine arteries) and maternal blood proteins (placental growth factor, soluble vascular endothelial growth factor receptor-1, pregnancy-associated plasma protein A). Such models require the transformation of biomarker data into multiples of the mean values by using population- and site-specific models. Previous studies have focused on a narrow window in gestation and have not included the maternal blood concentration of soluble endoglin, an important antiangiogenic factor up-regulated in preeclampsia.

OBJECTIVE

This study aimed (1) to develop models for the calculation of multiples of the mean values for mean arterial pressure and biochemical markers; (2) to build and assess the predictive models for preeclampsia based on maternal risk factors, the biophysical (mean arterial pressure) and biochemical (placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin) markers collected throughout pregnancy; and (3) to evaluate how prediction accuracy is affected by the presence of chronic hypertension and gestational age.

STUDY DESIGN

This longitudinal case-cohort study included 1150 pregnant women: women without preeclampsia with (n=49) and without chronic hypertension (n=871) and those who developed preeclampsia (n=166) or superimposed preeclampsia (n=64). Mean arterial pressure and immunoassay-based maternal plasma placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin concentrations were available throughout pregnancy (median of 5 observations per patient). A prior-risk model for preeclampsia was established by using Poisson regression based on maternal characteristics and obstetrical history. Next, multiple regression was used to fit biophysical and biochemical marker data as a function of maternal characteristics by using data collected at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, and observed values were converted into multiples of the mean values. Then, multivariable prediction models for preeclampsia were fit based on the biomarker multiples of the mean data and prior-risk estimates. Separate models were derived for overall, preterm, and term preeclampsia, which were evaluated by receiver operating characteristic curves and sensitivity at fixed false-positive rates.

RESULTS

(1) The inclusion of soluble endoglin in prediction models for all preeclampsia, together with the prior-risk estimates, mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1, increased the sensitivity (at a fixed false-positive rate of 10%) for early prediction of superimposed preeclampsia, with the largest increase (from 44% to 54%) noted at 20 to 23⁺⁶ weeks (McNemar test, P<.05); (2) combined evidence from prior-risk estimates and biomarkers predicted preterm preeclampsia with a sensitivity (false-positive rate, 10%) of 55%, 48%, 62%, 72%, and 84% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, and 28 to 31⁺⁶ week intervals, respectively; (3) the sensitivity for term preeclampsia (false-positive rate, 10%) was 36%, 36%, 41%, 43%, 39%, and 51% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, respectively; (4) the detection rate for superimposed preeclampsia among women with chronic hypertension was similar to that in women without chronic hypertension, especially earlier in pregnancy, reaching at most 54% at 20 to 23⁺⁶ weeks (false-positive rate, 10%); and (5) prediction models performed comparably to the Fetal Medicine Foundation calculators when the same maternal risk factors and biomarkers (mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1 multiples of the mean values) were used as input.

CONCLUSION

We introduced prediction models for preeclampsia throughout pregnancy. These models can be useful to identify women at risk during the first trimester who could benefit from aspirin treatment or later in pregnancy to inform patient management. Relative to prediction performance at 8 to 15⁺⁶ weeks, there was a substantial improvement in the detection rate for preterm and term preeclampsia by using data collected after 20 and 32 weeks' gestation, respectively. The inclusion of plasma soluble endoglin improves the early prediction of superimposed preeclampsia, which may be valuable when Doppler velocimetry of the uterine arteries is not available.

Aspirin for the prevention of pre-eclampsia in women with pre-existing diabetes: Systematic review

BACKGROUND

There is a lack of evidence for pre-eclampsia prophylaxis with aspirin in women with pre-existing diabetes mellitus (DM).

AIMS

To examine the evidence for aspirin in pre-eclampsia prophylaxis in women with pre-existing DM.

MATERIAL AND METHODS

An electronic search using Ovid MEDLINE, Embase, CinicalTrials.gov and the Cochrane CENTRAL register of controlled trials through to February 2021 was performed. Reference lists of identified studies, previous review articles, clinical practice guidelines and government reports were manually searched. Randomised controlled trials (RCTs) of aspirin vs placebo for pre-eclampsia prophylaxis were included. Articles were manually reviewed to determine if cohorts included women with DM. The systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data from included trials were extracted independently by two authors who also independently assessed risk of bias as per the Cochrane Handbook criteria version 5.1.0. Data were analysed using Rev-Man 5.4.

RESULTS

Forty RCTs were identified, of which 11 included a confirmed subset of women with DM; however, data were insufficient for meta-analysis. Meta-analysis of 930 women with DM, from individual patient data included in a systematic review and unpublished data from one of the 11 RCTs, showed a non-significant difference in the outcome of pre-eclampsia in participants treated with aspirin compared to placebo (odds ratio 0.58; 95% CI 0.20-1.71; P = 0.33).

CONCLUSIONS

Pre-eclampsia risk reduction with aspirin prophylaxis in women with pre-existing DM may be similar to women without pre-existing DM. However, randomised data within this meta-analysis were insufficient, warranting the need for further studies within this high-risk group of women.