Effects of low-dose aspirin on the prevention of preeclampsia and pregnancy outcomes: A randomized controlled trial from Shanghai, China

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.

Anti-hypertensive therapy for preeclampsia: a network meta-analysis and systematic review

BACKGROUND

Preeclampsia (PE) is a pregnancy disorder that represents a major cause of maternal and perinatal morbidity and mortality.

METHODS

This network meta-analysis was registered with PROSPERO. We searched the PubMed, ClinicalTrials.gov. and Embase databases for studies published from inception to the 31st of March 2023. RevMan5.3 software provided by the Cochrane Collaboration was used for direct meta-analysis (DMA) statistical analysis. Funnel maps, network meta-analysis (NMA), the surface under the cumulative ranking curve (SUCRA) to rank the different interventions and publication bias were generated by STATA 17.0 software.

RESULTS

We included eight randomized controlled trials (RCTs) involving a total of 1192 women with PE; two studies were of high quality and six were of moderate quality. Eight interventions were addressed in the NMA. In the DMA, we found that blood pressure in the Ketanserin group were significantly higher than those in the Nicardipine group. NMA showed that blood pressure in the Dihydralazine group was significantly higher than that in the Methyldopa, Labetalol, Nicardipine and Diltiazem groups. And the blood pressure in the Labetalol group was significantly lower than that in the Nicardipine group. SUCRA values showed that Diltiazem was more effective in lowering blood pressure than other drugs looked at in this study.

CONCLUSION

According to the eight RCTs included in this study, Diltiazem was the most effective in reducing blood pressure in PE patients; Labetalol and Nicardipine also had good effects. Diltiazem is preferred for the treatment of patients with severe PE and high blood pressure.

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.

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.

Association of dietary inflammatory index with risk of gestational diabetes mellitus and preeclampsia: a systematic review and meta-analysis

Findings from observational studies have suggested a possible association between dietary inflammatory index (DII) and risk of gestational diabetes mellitus (GDM) and preeclampsia (PE). However, the results of these studies were inconclusive. A systematic review and meta-analysis was carried out to illuminate this association. Systematic literature search was conducted in PubMed, Web of Science, Cochrane Library, EMBASE, Scopus and other databases from inception until January 2023. The qualities of included studies were assessed using the Newcastle-Ottawa scale. Nine studies (seven cohort, two case-control) were included in the meta-analysis, including 11 423 participants from five different countries. The meta-analysis indicated that a 1-unit increase in the DII score, representing pro-inflammatory diet, was associated with 13 % higher risk of GDM (OR = 1·13; 95 % CI 1·02, 1·25, I2 = 68·4 %, P = 0·004) and 24 % higher risk of PE (OR = 1·24; 95 % CI 1·14, 1·35, I2 = 52·0 %, P = 0·125). Subgroup analysis found that this association was evident among studies with Chinese populations (OR = 1·16; 95 % CI 1·06, 1·28) and studies with mid pregnancy (OR = 1·20; 95 % CI 1·07, 1·34). The findings indicate that pro-inflammatory diet can increase the risk of GDM and PE. Considering some limitations in this study, more studies are needed to verify this association.

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.

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.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Comparing aspirin 75 to 81 mg vs 150 to 162 mg for prevention of preterm preeclampsia: systematic review and meta-analysis

OBJECTIVE

This study aimed to compare 2 aspirin dosage regimens for the prevention of preterm preeclampsia (PE): 75 to 81 mg vs 150 to 162 mg taken daily starting in the first trimester of pregnancy.

DATA SOURCES

A systematic search was performed using PubMed, Embase, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials from January 1985 to April 2023.

STUDY ELIGIBILITY CRITERIA

The inclusion criteria were randomized controlled trials that compared the effect of 2 aspirin dosage regimens during pregnancy for the prevention of PE initiated in the first trimester of pregnancy. The intervention was an aspirin dosage between 150 and 162 mg daily, and the control was an aspirin dosage between 75 and 81 mg daily.

METHODS

Of note, 2 reviewers independently screened all citations, selected studies, and evaluated the risk of bias. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and applied the Cochrane risk of bias tool. The corresponding authors of the included studies were contacted to validate each of the collected results. The primary outcome was the risk of preterm preeclampsia, and the secondary outcomes included term preeclampsia, any preeclampsia regardless of gestational age, and severe preeclampsia. Relative risks with their 95% confidence interval were calculated for each study and pooled for global analysis.

RESULTS

Of note, 4 randomized controlled trials were retrieved involving 552 participants. Moreover, 2 randomized controlled trials were at unclear risk of bias, 1 trial at low risk of bias and 1 trial at high risk of bias, which did not have the information for the primary outcome. The pooled analysis demonstrated that an aspirin dosage of 150 to 162 mg was associated with a significant reduction of preterm preeclampsia, compared with an aspirin dosage of 75 to 81 mg (3 studies; 472 participants; relative risk, 0.34; 95% confidence interval, 0.15-0.79; P=.01; I2=0%). There was no significant effect on the risk of term preeclampsia (3 studies; 472 participants; relative risk, 0.57; 95% confidence interval, 0.12-2.64; P=.48; I2=64%) and all preeclampsia (4 studies; 552 participants; relative risk, 0.42; 95% confidence interval, 0.17-1.05; P=.06; I2=58%), but there was a reduction of severe preeclampsia (3 studies; 472 participantst; RR, 0.23; 95% CI, 0.09-0.62; P=.003; I2=0%).

CONCLUSION

When initiated in the first trimester of pregnancy, an aspirin dosage of 150 to 162 mg daily was associated with a lower risk of preterm PE than an aspirin dosage of 75 to 81 mg daily. However, the lack of large, high-quality studies limited the clinical scope of the current results taken alone.

Low-dose aspirin in the prevention of pre-eclampsia in China: postpartum hemorrhage in subgroups of women according to their characteristics and potential bleeding risk

BACKGROUND

The APPEC study is a large-population randomized controlled trial in China evaluating the role of low-dose aspirin prophylactic treatment for pre-eclampsia. There was no statistically significant difference in postpartum hemorrhage (PPH) incidence between the aspirin and control groups. This study aimed to evaluate the potential bleeding risk of 100 mg aspirin in high-risk pregnant women and the difference in the incidence of PPH according to maternal characteristics.

METHODS

This is a secondary data analysis of the APPEC study. Platelet counts and coagulation test results were collected at five follow-up visits. Subgroups defined by maternal age (<35 years and ≥35 years), pre-pregnancy body mass index (pre-BMI, <28 kg/m 2 and ≥28 kg/m 2 ), parity, gestational age at enrollment, and medical history, including pre-eclampsia, chronic hypertension, and diabetes mellitus, were analyzed. Logistic regression analysis was used to determine the statistical significance of the difference in the incidence of PPH after aspirin administration in pregnant women in each subgroup. Adjustment using multiple logistic regression models followed these analyses. Binary logistic regression was used to determine the relationship between pre-BMI and PPH.

RESULTS

There was no significant difference between the aspirin and control groups in bleeding risk (3.4% [16/464] vs. 3.0% [13/434], T = 0.147, P  = 0.701). No significant difference was found in the incidence of PPH in total (relative risk  = 1.220, 95% confidence interval [CI] = 0.720-2.067, P  = 0.459; aspirin group vs. control group, 6.5% [30/464] vs. 5.3% [23/434], P  = 0.459) or in subgroup analysis. A significant correlation between pre-BMI and PPH was found in the aspirin group, while in the control group there was no significant correlation (aspirin group, odds ratio [OR] = 1.086, 95% CI = 1.004-1.175, P  = 0.040; control group, OR = 1.060, 95% CI = 0.968-1.161, P  = 0.209).

CONCLUSIONS

A dosage of 100 mg of aspirin per day, initiated from 12 to 20 gestational weeks until 34 weeks of gestation, did not increase the risk of potential bleeding and PPH regardless of the maternal characteristic. In the aspirin group, the positive correlation between BMI and PPH was significant.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01979627.

Clinical practice guidelines on the use of aspirin in pregnancy: Systematic review

BACKGROUND

Placental related disorders, including preeclampsia and fetal growth restriction (FGR) are among the main determinants of adverse maternal and perinatal outcomes in both singleton and twin pregnancies. In view of its relevance, aspirin administration is commonly recommended to women at high risk for preeclampsia or FGR by the various national and international guidelines.

OBJECTIVES

To establish the clinical heterogeneity among the clinical practice guidelines (CPGs) on aspirin use in pregnancy and to investigate the quality of these CPGs.

METHODS

We performed a systematic review of Clinical practice guidelines on main databases searching for all peer-reviewed guidelines into the literature, analyzing the following aspects related to use of aspirin in pregnancy: indications for aspirin administration, dosage, starting of therapy, ending of therapy, safety and side effects. The assessment of risk of bias and quality assessment of the included CPGs were performed using "The Appraisal of Guidelines for REsearch and Evaluation (AGREE II)" tool.

RESULTS

16 CPGs were included. There was an overall general agreement among the published CPGs as regards to the indication for aspirin intake in pregnancy, with prior preeclampsia, chronic hypertension, autoimmune disease, and diabetes mellitus type 1 or 2 recognized as solitary major risk factors for Aspirin administration in 93.7% (15/16) of CPGs. There was heterogeneity in the recommendations provided by the different CPGs as regards the gestational age at which aspirin should be commenced.

CONCLUSION

There is general agreement in the reported indications for aspirin intake in pregnancy, with prior preeclampsia and maternal medical co-morbidity associated with increased risk of preeclampsia being the major indications for aspirin intake. Conversely, there was heterogeneity in the recommended dose, gestational age at initiation and discontinuation of therapy among the different CPGs.

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 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.

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].

Platelet aggregation in normal pregnancy

It was recently shown that abnormal platelet aggregation (PA) had played a critical role in some adverse pregnancies. Till now reference range for PA in normal pregnancy has not been determined. Furthermore, few study has been conducted to explore the factors related to PA. Our study was performed to assess the reference range of PA in normal pregnancy (150 participants in the second trimester), and to determine whether it differs from that of the controls (38 nonpregnant participants). In addition, this study explored the factors related to PA. The results showed that PA was significantly higher in normal pregnancy than that in the controls (84.40% vs. 80.7%, respectively, P = 0.013). The reference interval for PA in normal pregnancy was 74.75%-94.77%. Hemoglobin (Hb), platelet counts (PLT) and albumin (Alb) were significant lower in normal pregnancy than those in the control group. Moreover, it was found that PA was positively correlated with PLT (r = 0.263, P < 0.001), and negatively correlated with platelet distribution width (PDW) (r = -0.342, P < 0.001) and mean platelet volume (r = -0.296, P < 0.001). Linear correlations between PA and Alb, PDW were proved by linear regression model (LRM). In conclusion, PA was enhanced in normal pregnancy, and Alb and PDW might be the possible contributing factors to PA.

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.

Hypertensive disorders of pregnancy: definition, management, and out-of-office blood pressure measurement

Hypertensive disorders of pregnancy increase the risk of adverse maternal and fetal outcomes. In 2018, the Japanese classification of hypertensive disorders of pregnancy was standardized with those of other countries, and a hypertensive disorder of pregnancy was considered to be present if hypertension existed during pregnancy and up to 12 weeks after delivery. Strategies for the prevention of hypertensive disorders of pregnancy have become much clearer, but further research is needed on appropriate subjects and methods of administration, and these have not been clarified in Japan. Although guidelines for the use of antihypertensive drugs are also being studied and standardized with those of other countries, the use of calcium antagonists before 20 weeks of gestation is still contraindicated in Japan because of the safety concerns that were raised regarding possible fetal anomalies associated with their use at the time of their market launch. Chronic hypertension is now included in the definition of hypertensive disorders of pregnancy, and blood pressure measurement is a fundamental component of the diagnosis of hypertensive disorders of pregnancy. Out-of-office blood pressure measurements, including ambulatory and home blood pressure measurements, are important for pregnant and nonpregnant women. Although conditions such as white-coat hypertension and masked hypertension have been reported, determining their occurrence in pregnancy is complicated by the gestational week. This narrative review focused on recent reports on hypertensive disorders of pregnancy, including those related to blood pressure measurement and classification.

Impact of low-dose acetylsalicylic acid on pregnancy outcome in systemic lupus erythematosus: results from a multicentre study

Objective

It is still a matter of debate whether low-dose acetylsalicylic acid (LDASA) should be prescribed to all patients with SLE during pregnancy. This study aimed at investigating the impact of LDASA on pregnancy outcomes in patients with SLE without history of renal involvement and without antiphospholipid antibodies (aPL).

Methods

This is a retrospective analysis of prospectively monitored pregnancies at seven rheumatology centres. Previous/current renal involvement and aPL positivity were the exclusion criteria. Adverse pregnancy outcome (APO) is the composite outcome of the study and included proteinuric pre-eclampsia, preterm delivery <37 weeks, small-for-gestational age infant, low birth weight <2500 g, intrauterine growth restriction and intrauterine fetal death after 12 weeks of gestation of a morphologically normal fetus.

Results

216 pregnancies in 187 patients were included; 82 pregnancies (38.0%) were exposed to LDASA treatment. No differences in terms of age at conception, disease duration, clinical manifestations, comorbidities and disease flare during pregnancy were observed between patients taking LDASA and those who did not take LDASA during pregnancy. APO was observed in 65 cases (30.1%), including 13 cases (6.1%) of pre-eclampsia. The incidence of all complications was similar in the two groups. However, it is interesting to note that pre-eclampsia had lower frequency in patients taking LDASA versus those not taking LDASA (2.4% vs 8.3%, p=0.14).

Conclusions

In pregnant patients with SLE without renal involvement and were aPL-negative, there is a low risk of severe obstetric complications, such as early pre-eclampsia. LDASA treatment does not provide a statistically significant advantage over these complications. However, a careful individual risk–benefit balance is warranted.

Evaluation of maternal serum progesterone-induced blocking factor levels in pregnancies complicated with early- and late-onset preeclampsia

The aim of present study was to evaluate maternal serum progesterone-induced blocking factor (PIBF) levels in pregnancies complicated with early-onset (EO-PE) and late-onset (LO-PE) preeclampsia. Patients with preeclampsia were divided in two groups according to preeclampsia onset and compared to healthy control group: EO-PE and LO-PE defined as being diagnosed before 340/7 and ≥340/7 weeks, respectively. Maternal age, nulliparity, BMI at blood sampling, smoking, history of caesarean section and ethnicity were statistically similar among the groups. Statistically significant differences were found between the eo-PE and lo-PE preeclampsia groups in terms of gestational age at delivery, mean birth-weight percentile and foetal growth restriction rates. The mean serum PIBF level was 528.6 ± 220 ng/mL in the eo-PE and 615.3 ± 269.1 ng/mL in the lo-PE preeclampsia and 782.3 ± 292.4 ng/mL in the control groups; the difference among groups was statistically significant. Our results indicated that decreased PIBF levels play an important immunologic role in preeclampsia onset. IMPACT STATEMENTWhat is already known on this subject? Maternal lymphocytes secrete PIBF that provides the immunological effects of progesterone during pregnancy by activating T-helper type 2 (Th2) cells and inhibiting any activated uterine natural killer (uNK) cells. The recent studies results have shown that there is disproportion in the Th1/Th2 rate in women with preeclampsia. This purports that Th1-mediated immunity is promoted through Th2-mediated immunity, which can be involved in the pathogenesis of preeclampsia.What do the results of this study add? In this study we found that PIBF levels in maternal serum were significantly lower in the EO-PE group than in LO-PE and control group. Our results indicated that decreased PIBF levels play an important immunologic role in preeclampsia onset.What are the implications of these findings for clinical practice and/or further research? We can speculate that first trimester maternal serum PIBF levels may be a useful biomarker for prediction of EO-PE. Using serum PIBF levels within the first trimester combined with Doppler values for the uterine artery, and some biochemical markers to predict onset and severity of preeclampsia appear to be a new screening method.

Low-dose aspirin improves blood perfusion of endometrium of unexplained recurrent biochemical pregnancy loss

OBJECTIVE

To assess the differences in Doppler parameters of endometrial receptivity in unexplained recurrent biochemical pregnancy loss (URBPL) and the therapeutic effect of low-dose aspirin (LDA).

METHODS

A retrospective study was conducted at Ren Ji Hospital, Shanghai, PR China, from January 2017 to January 2019. Doppler parameters of endometrium and uterus were recorded as the evaluation of the endometrial receptivity. Receiver operating characteristic (ROC) curve was managed to predict the risk of URBPL. Ultrasonography tests were repeated after 2 months of treatment with LDA.

RESULTS

Biochemical pregnancies did not correlate with maternal age. The resistance of endometrial perfusion (pulsatility index, resistive index, and systolic-to-diastolic ratio) was significantly higher in URBPLs (P < 0.001) and had predictive values (0.739, 0.779, and 0.760, respectively). Endometrial thickness and impedance to uterine blood flow showed no statistically significant difference (P > 0.05). After treatment with LDA, patients with URBPL improved the blood perfusion of endometrium significantly (P < 0.01).

CONCLUSION

There was no relation between BPL and maternal age. Patients with URBPL had inappropriate endometrial blood velocity. Doppler indices are capable of predicting the risk of URBPL. LDA exerts the therapeutic effect on improving blood perfusion of endometrium in URBPL.

Aspirin Prophylaxis During Pregnancy: A Systematic Review and Meta-Analysis

CONTEXT

Low-dose aspirin is used for pre-eclampsia prophylaxis during pregnancy, but a study that comprehensively investigates both maternal and perinatal outcomes from aspirin administration utilizing stratification methods is lacking. The aim of this study is to comprehensively investigate the maternal and neonatal outcomes related to aspirin prophylaxis during pregnancy in relation to dose and therapy initiation by utilizing a stratification method.

EVIDENCE ACQUISITION

Placebo-controlled randomized trials investigating the effect of low-dose aspirin on maternal or perinatal outcomes with sufficient raw data and published in English from inception to August 2020 were searched for from PubMed, Embase, Cochrane Library, and Google Scholar in accordance with PRISMA guidelines. Review articles, editorials, case reports, conference abstracts, and nonplacebo-controlled studies were excluded.

EVIDENCE SYNTHESIS

A total of 35 placebo-controlled randomized trials with 46,568 pregnant women were included in this meta-analysis. Aspirin prophylaxis substantially lowered the risk of pre-eclampsia, preterm birth, perinatal mortality, and intrauterine growth retardation without elevated bleeding risks. Low-dose aspirin considerably enhanced neonatal birth weight but did not decrease the risk of gestational hypertension. The subgroup analysis revealed substantially reduced pre-eclampsia risk and enhanced birth weight and gestational age at delivery in women who initiated aspirin before 20 weeks of gestation (RR=0.76, 95% CI=0.64, 0.90, p=0.001). However, the effect of aspirin dose on pregnancy outcomes was insignificant and requires further evaluation.

CONCLUSIONS

Initiation of low-dose aspirin administration before 20 weeks of gestation considerably decreases the incidence of pre-eclampsia and related neonatal outcomes without increasing bleeding risk.

Low-Dose Aspirin Prevents Kidney Damage in LPS-Induced Preeclampsia by Inhibiting the WNT5A and NF-κB Signaling Pathways

Preeclampsia (PE) is a serious pregnancy-related disease, and patients usually present with a high inflammatory response. Previous studies have suggested that aspirin (ASP) may have a role in alleviating the pathogenesis of preeclampsia. However, whether ASP can improve kidney damage and the mechanism for improving it is currently unclear. Here we optimized a lipopolysaccharide (LPS)-induced PE mouse model to identify the role of ASP in renal protection. We found that ASP treatment ameliorated LPS-induced renal failure and pathological changes, the tubular injury was significantly attenuated by ASP. Administration of ASP decreased the renal expression of pro-inflammatory factors, resulting in reduced kidney inflammation. The number of GALECTIN-3-positive cells was reduced, and the up-regulation of IL-6 and TNF-α was decreased. In addition, ASP also suppressed renal cell apoptosis and oxidative stress. An in vitro study indicated that ASP relieved LPS-induced HK-2 cell damage by inhibiting WNT5A/NF-κB signaling. Collectively, our data suggest that ASP is a useful therapeutic option for PE-related kidney injury.