A meta-analysis of low-dose aspirin for prevention of preeclampsia

The effectiveness of low-dose aspirin for the prevention of hypertensive disorders of pregnancy in a sub-Saharan Africa Country: A randomized clinical trial

OBJECTIVE

To evaluate whether a daily dose of low-dose aspirin (LDA) can prevent hypertensive disorders of pregnancy (HDP), including preeclampsia, among pregnant women in a South African cohort, and to assess its impact on related maternal and fetal outcomes, such as preterm birth and neonatal complications.

STUDY DESIGN

This single-center, open-label, parallel-group randomized controlled trial (RCT) was conducted at a regional hospital in Durban, KwaZulu-Natal, South Africa, from May 2021 to March 2024. A total of 423 pregnant women, aged 18 years or older with singleton pregnancies between 12 and 20 weeks of gestation, were randomized to receive either 162 mg of LDA daily or standard care. The primary outcome was the incidence of HDP, while secondary outcomes included early-onset preeclampsia (EOPE), preterm birth, low birth weight (LBW), and neonatal death. Data analysis used relative risk (RR) and 95 % confidence intervals (CIs).

RESULTS

Of the 423 women, 209 were in the LDA group and 214 in the control group. The incidence of HDP was significantly lower in the LDA group (6.2 % vs. 25.2 %; RR = 0.25, 95 % CI [0.14-0.44], p < 0.001), corresponding to a 75 % reduction in HDP risk, with an absolute risk reduction (ARR) of 19 % and a number needed to treat (NNT) of 5.3. EOPE was reduced (2.4 % vs. 14.0 %; RR = 0.17, 95 % CI [0.07-0.41], p < 0.001), as was preterm birth (6.7 % vs. 26.2 %; RR = 0.26, 95 % CI [0.15-0.45], p < 0.001). There were no significant differences for LBW or neonatal death. Sensitivity analysis confirmed the importance of initiating LDA before 16 weeks, showing continued reductions in HDP incidence with early initiation.

CONCLUSION

LDA significantly reduces the risk of HDP, EOPE, and preterm birth, particularly when initiated before 16 weeks of gestation. These findings support the use of LDA for preventing hypertensive disorders of pregnancy in low-resource settings and underscore the value of early intervention for improved maternal and fetal outcomes.

Management of Acne in Pregnancy

Acne is one of the most common dermatological conditions to affect women of childbearing age, so it is important to consider the safety of long-term acne treatments on women who could become pregnant. In this review article, we clarify what management options are available to treat acne during pregnancy. Topical treatments, typically first-line for acne, such as azelaic acid, clindamycin, erythromycin, metronidazole, benzoyl peroxide, salicylic acid, dapsone, and retinoids, were reviewed. Systemic treatments, such as zinc supplements, cephalexin, cefadroxil, amoxicillin, azithromycin, erythromycin, and corticosteroids, typically second-line for acne, were also reviewed. Alternative treatments such as light therapy and cosmetic procedures were also evaluated. Due to recommendation of sunscreen utilization during acne treatments, sunscreen usage during pregnancy was also assessed. Management of acne during unplanned pregnancy was discussed in further detail regarding safety and adverse effects. Through summarized tables and examples of studies demonstrating safety and efficacy of treatments, the following is a resource for providers and patients to utilize for management of acne during pregnancy.

Prophylactic aspirin for preventing pre-eclampsia and its complications: An overview of meta-analyses

Benefits of aspirin administration on pre-eclampsia and IUGR depend on the gestational age and dose of aspirin administration. Meta-analyses show that, to prevent preterm labor, aspirin could be administrated even after 16 weeks of gestational age.

Antiplatelet agents for preventing pre-eclampsia and its complications

BACKGROUND

Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, low-dose aspirin in particular, might prevent or delay development of pre-eclampsia.

OBJECTIVES

To assess the effectiveness and safety of antiplatelet agents, such as aspirin and dipyridamole, when given to women at risk of developing pre-eclampsia.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (30 March 2018), and reference lists of retrieved studies. We updated the search in September 2019 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

All randomised trials comparing antiplatelet agents with either placebo or no antiplatelet agent were included. Studies only published in abstract format were eligible for inclusion if sufficient information was available. We would have included cluster-randomised trials in the analyses along with individually-randomised trials, if any had been identified in our search strategy. Quasi-random studies were excluded. Participants were pregnant women at risk of developing pre-eclampsia. Interventions were administration of an antiplatelet agent (such as low-dose aspirin or dipyridamole), comparisons were either placebo or no antiplatelet.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trials for inclusion and extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For this update we incorporated individual participant data (IPD) from trials with this available, alongside aggregate data (AD) from trials where it was not, in order to enable reliable subgroup analyses and inclusion of two key new outcomes. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.

MAIN RESULTS

Seventy-seven trials (40,249 women, and their babies) were included, although three trials (relating to 233 women) did not contribute data to the meta-analysis. Nine of the trials contributing data were large (> 1000 women recruited), accounting for 80% of women recruited. Although the trials took place in a wide range of countries, all of the nine large trials involved only women in high-income and/or upper middle-income countries. IPD were available for 36 trials (34,514 women), including all but one of the large trials. Low-dose aspirin alone was the intervention in all the large trials, and most trials overall. Dose in the large trials was 50 mg (1 trial, 1106 women), 60 mg (5 trials, 22,322 women), 75mg (1 trial, 3697 women) 100 mg (1 trial, 3294 women) and 150 mg (1 trial, 1776 women). Most studies were either low risk of bias or unclear risk of bias; and the large trials were all low risk of bas. Antiplatelet agents versus placebo/no treatment The use of antiplatelet agents reduced the risk of proteinuric pre-eclampsia by 18% (36,716 women, 60 trials, RR 0.82, 95% CI 0.77 to 0.88; high-quality evidence), number needed to treat for one women to benefit (NNTB) 61 (95% CI 45 to 92). There was a small (9%) reduction in the RR for preterm birth <37 weeks (35,212 women, 47 trials; RR 0.91, 95% CI 0.87 to 0.95, high-quality evidence), NNTB 61 (95% CI 42 to 114), and a 14% reduction infetal deaths, neonatal deaths or death before hospital discharge (35,391 babies, 52 trials; RR 0.85, 95% CI 0.76 to 0.95; high-quality evidence), NNTB 197 (95% CI 115 to 681). Antiplatelet agents slightly reduced the risk of small-for-gestational age babies (35,761 babies, 50 trials; RR 0.84, 95% CI 0.76 to 0.92; high-quality evidence), NNTB 146 (95% CI 90 to 386), and pregnancies with serious adverse outcome (a composite outcome including maternal death, baby death, pre-eclampsia, small-for-gestational age, and preterm birth) (RR 0.90, 95% CI 0.85 to 0.96; 17,382 women; 13 trials, high-quality evidence), NNTB 54 (95% CI 34 to 132). Antiplatelet agents probably slightly increase postpartum haemorrhage > 500 mL (23,769 women, 19 trials; RR 1.06, 95% CI 1.00 to 1.12; moderate-quality evidence due to clinical heterogeneity), and they probably marginally increase the risk of placental abruption, although for this outcome the evidence was downgraded due to a wide confidence interval including the possibility of no effect (30,775 women; 29 trials; RR 1.21, 95% CI 0.95 to 1.54; moderate-quality evidence). Data from two large trials which assessed children at aged 18 months (including results from over 5000 children), did not identify clear differences in development between the two groups.

AUTHORS' CONCLUSIONS

Administering low-dose aspirin to pregnant women led to small-to-moderate benefits, including reductions in pre-eclampsia (16 fewer per 1000 women treated), preterm birth (16 fewer per 1000 treated), the baby being born small-for-gestational age (seven fewer per 1000 treated) and fetal or neonatal death (five fewer per 1000 treated). Overall, administering antiplatelet agents to 1000 women led to 20 fewer pregnancies with serious adverse outcomes. The quality of evidence for all these outcomes was high. Aspirin probably slightly increased the risk of postpartum haemorrhage of more than 500 mL, however, the quality of evidence for this outcome was downgraded to moderate, due to concerns of clinical heterogeneity in measurements of blood loss. Antiplatelet agents probably marginally increase placental abruption, but the quality of the evidence was downgraded to moderate due to low event numbers and thus wide 95% CI. Overall, antiplatelet agents improved outcomes, and at these doses appear to be safe. Identifying women who are most likely to respond to low-dose aspirin would improve targeting of treatment. As almost all the women in this review were recruited to the trials after 12 weeks' gestation, it is unclear whether starting treatment before 12 weeks' would have additional benefits without any increase in adverse effects. While there was some indication that higher doses of aspirin would be more effective, further studies would be warranted to examine this.

Preeclampsia: Short-term and Long-term Implications

Preeclampsia is a hypertensive disorder that affects 4% of pregnancies and has a high risk of maternal, fetal, and neonatal morbidity and mortality, as well as long-term cardiovascular risk. Recent updates in the definition, diagnosis, and management guidelines for preeclampsia warrant review by general obstetrician-gynecologists. Screening and prevention algorithms for preeclampsia are available, but ultimately the cure remains delivery of the fetus and placenta. Close monitoring for the development and worsening of preeclampsia during pregnancy is essential to optimize both maternal and fetal/neonatal outcomes.

Lack of Thromboxane Synthase Prevents Hypertension and Fetal Growth Restriction after High Salt Treatment during Pregnancy

Preeclampsia (PE) is a potentially fatal pregnancy-related hypertensive disorder characterized by poor placenta development that can cause fetal growth restriction. PE-associated pathologies, including thrombosis, hypertension, and impaired placental development, may result from imbalances between thromboxane A₂ (TXA₂) and prostacyclin. Low-dose aspirin, which selectively inhibits TXA₂ production, is used to prevent high-risk PE. However, the role of TXA₂ in aspirin-mediated protective effects in women with PE is not understood fully. In this study, we examined the role of prostanoids in PE using human samples and an induced PE mouse model. We demonstrated that the administration of salted drinking water (2.7% NaCl) to wild-type mice resulted in elevated placental TXA₂ synthase (TXAS) and plasma TXA₂, but not prostacyclin, levels, which was also found in our clinical PE placenta samples. The high salt-treated wild-type pregnant mice had shown unchanged maternal body weight, hypertension (MAP increase 15 mmHg), and decreased pup weight (~50%) and size (~24%), but these adverse effects were ameliorated in TXAS knockout (KO) mice. Moreover, increased expression of interleukin-1β and downstream phosphorylated-p38-mitogen-activated protein kinase were concordant with apoptosis induction in the placentas of salt water-treated wild-type mice. These alterations were not observed in TXAS KO mice. Together, our data suggest that TXA₂ depletion has anti-PE effects due to the prevention of hypertension and placental damage through downregulation of the interleukin-1β pathway.

[Analysis of the causes for increases in the length of stay in the Recovery Unit of La Paz Maternity Hospital in 2008]

OBJECTIVE

To establish the spectrum of diseases in the obstetric patient that involves an increase in the length of stay in the Recovery Unit of a specialist Maternity Hospital. To analyse the severity of these conditions as regards the means required for their resolu-tion, as well as to identify the factors that influence on post-operative morbidity in the obstetric patient.

MATERIAL AND METHODS

All the case histories of all the patients admitted to the Maternity Hospital Recovery Unit during the year 2008 were reviewed. Those who required a lon-ger stay than usual were selected, which included, those with more than 6hours after a caesarean, and all admissions made during pregnancy, or after dilation and curettage or partum.

RESULTS

Out of a total of 10419 births delivered in 2008, 3000 obstetric patients were ad-mitted to the Maternity Hospital Recovery Unit, of which 285 (9.5%) required critical care. The most frequent cause of increased length of stay was obstetric haemorrhage, followed by hypertensive states of pregnancy. No patients died in this Unit in the year 2008.

CONCLUSIONS

The number of patients who had an increased length of stay in the Mater-nity Hospital Recovery Unit is similar to the percentage of patients who are admitted to Intensive Care Units in countries such as Canada or the United Kingdom, but our Unit had a lower death rate in the year evaluated. The main causes are obstetric haemorrhage and hypertensive states of pregnancy, thus patients with risk factors for developing these complications must be observed closely and monitored.

Treatment of high risk pregnancies

Introduction: The efficacy of a therapy with certoparin; also in combination with aspirin and prednisolone; in high-risk pregnancies has been examined prospectively.

Method: Data of 616 pregnancies have been analyzed. 238 patients injected Mono Embolex 3000; 239 patients Mono Embolex 8000 only. 62 patients injected Mono Embolex 8000 and took aspirin 50–100 mg daily; 60 Mono Embolex 3000 and aspirin 50–100 mg daily. 30 patients took aspirin 50–100 mg; prednisolone 2.5–5 mg and 17 injected mono Embolex 8000; 13 Mono Embolex 3000 daily from the start of their pregnancy. The target variable was the life birth rate.

When given aspirin the HPA-status of the partner is measured if the pregnant woman is negative for HPA 1a or 5b. In HPA-negative mothers and HPA-positive fathers a test for HPA-antibodies is performed posterior week 16.

Result: Applied early; a mean life birth rate of 95 % has been achieved in the monotherapy with Mono Embolex. Where heparin and aspirin were applied before pregnancy week 17 a life birth rate of 100 % was achieved. In patientswith a combination of aspirin and prednisolone a life birth rate of 87 % was achieved. Considering the life birth rate the status of thrombophilia gene-polymorphisms is irrelevant. The HPA-status was examined in 139 patients. In one of the HPA 5a-negative and 3 of the HPA 5b-negative women an immunization occurred but the platelet count of the fetus was not decreased. 3.3 % showed local allergic reaction and 0.5 % slight bleeding.

Conclusion: Certoparin, aspirin and prednisolone are safe drugs to increase life birth rate.

Preeclampsia from a renal point of view: Insides into disease models, biomarkers and therapy

Proteinuria is a frequently detected symptom, found in 20% of pregnancies. A common reason for proteinuria in pregnancy is preeclampsia. To diagnose preeclampsia clinically and to get new insights into the pathophysiology of the disease it is at first essential to be familiar with conditions in normal pregnancy. Animal models and biomarkers can help to learn more about disease conditions and to find new treatment strategies. In this article we review the changes in kidney function during normal pregnancy and the differential diagnosis of proteinuria in pregnancy. We summarize different pathophysiological theories of preeclampsia with a special focus on the renal facets of the disease. We describe the current animal models and give a broad overview of different biomarkers that were reported to predict preeclampsia or have a prognostic value in preeclampsia cases. We end with a summary of treatment options for preeclampsia related symptoms including the use of plasmapheresis as a rescue therapy for so far refractory preeclampsia. Most of these novel biomarkers for preeclampsia are not yet implemented in clinical use. Therefore, we recommend using proteinuria (measured by UPC ratio) as a screening parameter for preeclampsia. Delivery is the only curative treatment for preeclampsia. In early preeclampsia the primary therapy goal is to prolong pregnancy until a state were the child has an acceptable chance of survival after delivery.

Aspirin for prevention of preeclampsia in lupus pregnancy

Preeclampsia, the onset of hypertension and proteinuria during pregnancy, is a common medical disorder with high maternal and fetal mortality and morbidity. The underlying pathology remains poorly understood and includes inflammation, endothelial dysfunction, and an unbalanced thromboxane A₂/prostacyclin ratio. For women with systemic lupus erythematosus (SLE), particularly those with preexisting renal disease or with active lupus, the risk of developing preeclampsia is up to 14% higher than it is among healthy individuals. The mechanism is still unknown and the data for preventing preeclampsia in lupus pregnancies are rare. Modulating the impaired thromboxane A₂/prostacyclin ratio by administration of low-dose aspirin appears to be the current best option for the prevention of preeclampsia. After providing an overview of the pathogenesis of preeclampsia, preeclampsia in lupus pregnancies, and previous trials for prevention of preeclampsia with aspirin treatment, we recommend low-dose aspirin administration for all lupus patients starting prior to 16 weeks of gestation. Patients with SLE and antiphospholipid syndrome should receive treatment with heparin and low-dose aspirin during pregnancy.

Management of chronic hypertension during pregnancy with furosemide, amlodipine or aspirin: a pilot clinical trial

OBJECTIVE

To determine the maternal and neonatal efficacy and safety with furosemide, amlodipine or aspirin in women with mild/moderate chronic hypertension during pregnancy.

METHODS

A pilot clinical trial was performed in a tertiary teaching hospital in Panama. Pregnant patients with mild/moderate chronic hypertension at ≤20 weeks of gestation were invited to take part in the study. Mild/moderate chronic hypertension was defined as a pregnancy with systolic blood pressure of 140-159 mmHg or diastolic blood pressure of 90-109 mmHg. Women in the furosemide group received 20 mg of furosemide oral each day, those in the amlodipine group received 5 mg of amlodipine oral each day and those in the aspirin group received 75 mg of orally-administered acetylsalicylic acid each day.

RESULTS

We enrolled 63 patients during the study period, 21 women were randomised to each group (aspirin, amlodipine and furosemide). We found no difference in maternal complications, pre-term births, mean birth weight or in the proportion of small for gestational age infants among treatment groups. Severe hypertension and aggregate pre-eclampsia were similar among treatment groups.

CONCLUSION

This pilot trial demonstrates that both furosemide and amlodipine might have the same effect during pregnancy. However, a large clinical trial is necessary to prove this.

Individual risk assessment of adverse pregnancy outcome by multivariate regression analysis may serve as basis for drug intervention studies: retrospective analysis of 426 high-risk patients including ethical aspects

OBJECTIVE

To identify patients at very high risk for adverse pregnancy outcome (APO) at the 20- to 23-week scan and to assess the effectiveness of Aspirin (ASS) and low molecular weight heparin (LMWH) starting after this examination.

PATIENTS AND METHODS

By applying an algorithm based on multivariate logistic regression analysis using the parameters maternal age, parity, body mass index (BMI), mean pulsatility index of both uterine arteries (meanPI), presence of uni- or bilateral notch, and depth of notch (mean notch index (meanNI), we retrospectively calculated the individual risk for APO of 21,302 singleton pregnancies. We isolated a subgroup of 426 patients with the highest calculated probability for APO (cpAPO > 27.8 %). 147 had been treated with ASS; 73 with LMWH, 15 patients with a combination of ASS and LMWH, and 191 patients had not received anticoagulants.

RESULTS

Administration of ASS starting after 20 gestational weeks in comparison to non-treated patients significantly reduced the frequency of intrauterine/neonatal death (IUD/NND), preeclampsia <33 weeks (PE < 33), and preterm delivery <33 weeks (PD < 33), while the frequency of IUGR showed a tendency to be elevated (P = 0.061). The subgroup of high-risk patients treated with LMWH was characterised by a higher a priori risk for APO and showed no significant reduction of any form of APO but an increased frequency of PE.

CONCLUSION

Individual assessment of risk for APO by applying a simple algorithm based on biometrical/biographical as well as sonographic parameters may serve as basis for drug intervention studies. The administration of ASS in high-risk patients starting after 20 gestational weeks reduced the frequency of most of the severe forms of adverse pregnancy outcome in high-risk patients. A complication-reducing effect of LMWH starting after 20 weeks of gestation in patients could not be proven. From an ethical point of view, it may not be justified any more to preclude high-risk patients from administration of ASS or to perform studies of ASS against placebo.

Fertility and pregnancy in vasculitis

Despite the rarity of vasculitides, fertility and pregnancy outcome in the setting of vasculitis have become a major topic of interest within the past decade. The potential impact of vasculitis therapies, particularly cyclophosphamide, has been examined to some extent, but data are limited on the possible impact of the disease itself on fertility. Ideally, pregnancy should be planned when the vasculitis is in remission. The outcome for mothers and newborns is usually good when vasculitis is known before the pregnancy and is in remission, but every pregnant woman must be monitored by a specialised health-care team consisting of obstetricians specialised in high-risk births and internists/rheumatologists with expertise in managing these rare conditions. Most maternal complications during pregnancy are indeed due to vasculitis damage: hypertension in Takayasu arteritis (TAK) or granulomatosis with polyangiitis (GPA)/microscopic polyangiitis (MPA) with renal insufficiency, asthma or cardiac damage in eosinophilic granulomatosis with polyangiitis (EGPA) and subglottic and/or bronchial stenosis(es) in GPA. Pregnancy loss can occur in about 10% of cases in GPA, up to 20% in EGPA, 20-30% in Behçet's disease and up to 25% in TAK, and several studies found high rates of preterm births, at least with some vasculitides. Vasculitis manifestations in newborns from mothers with known vasculitis are very rare and usually transient.

Nonsteroidal anti-inflammatory drugs during pregnancy and the initiation of lactation

Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin, which are available as "over-the counter" medications in most countries, are widely used by both pregnant and lactating women. They are popular non-opioid analgesics for the treatment of pain after vaginal and operative delivery. In addition, NSAIDs are used for tocolysis in premature labor, and low-dose aspirin has a role in the prevention of preeclampsia and recurrent miscarriage in antiphospholipid syndrome. NSAIDs and aspirin may affect fertility and increase the risk of early pregnancy loss. In the second trimester their use is considered reasonably safe, but has been associated with fetal cryptorchism. In the third trimester, NSAIDs and aspirin are usually avoided because of significant fetal risks such as renal injury, oligohydramnios, constriction of the ductus arteriosus (with potential for persistent pulmonary hypertension in the newborn), necrotizing enterocolitis, and intracranial hemorrhage. Maternal administration or ingestion of most NSAIDs results in low infant exposure via breastmilk, such that both cyclooxygenase-1 and cyclooxygenase-2 inhibitors are generally considered safe, and preferable to aspirin, when breastfeeding.

Why hypertension is good new and preeclampsia bad news-demonstrating the failure of prevention

Hypertensive disorders in pregnancy continue to be an intriguing and potentially lethal complication in humans and some other primates. In a simplistic way the current hypothesis is that the genesis of preeclampsia starts at 12 to 14 wk gestation with failure of trophoblast invasion in the spiral arteries, resulting in some degree of hypoxemia in the placenta. The hypoperfused placental tissue starts to secrete variable amounts of angiogenic and antiangiogenic factors which eventually cause endothelial damage all over the pregnant women’s body with one of the many signs of preeclampsia as the clinical endpoint. For some incomprehensible reason a major interest has existed for decades concerning the early prediction of preeclampsia, most commonly tested using uterine artery Doppler (the earlier the better) and various serum markers, alone or in combination. Any new model for detection has been welcomed enthusiastically, although nothing has changed in the outcome of women presenting with preeclampsia.