Spontaneous Preterm Birth: Is Prevention with Aspirin Possible?

Low-dose aspirin for the prevention of preterm birth in nulliparous women: systematic review and meta-analysis

OBJECTIVE

The objective was to assess the efficacy and safety of low-dose aspirin for the prevention of preterm birth in nulliparous women.

DATA SOURCES

We searched PubMed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to June 2022.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared aspirin to placebo in nulliparous women were eligible.

METHODS

This study was reported in accordance with the PRISMA 2020 checklist. The primary outcomes of this study were the rates of preterm birth at less than 37 weeks and less than 34 weeks of gestation. The secondary outcomes included postpartum hemorrhage, placental abruption, cesarean section, any hypertensive disorder of pregnancy and small for gestational age. Relative risks with their 95% confidence intervals were calculated for analysis. Heterogeneity was assessed by Cochran's Q test and Higgins's I2. A random-effects model was used when I2 was > 50% to generate the RR and 95% CI; otherwise, a fixed-effects model was used. The risk of publication bias was assessed by funnel plots. We performed sensitivity analysis by sequentially omitting each included study to confirm the robustness of the analysis.

RESULTS

Seven studies with a total of 29,029 participants were included in this review. Six studies were assessed as having a low risk of bias or an unclear risk of bias, and one study was judged as having a high risk of bias. In nulliparous women, low-dose aspirin was associated with a significant reduction in the rate of preterm birth at less than 34 weeks of gestational age (RR 0.84,95% CI: 0.71-0.99; I2 = 0%; P = 0.04), but we did not observe a significant difference in the rate of preterm birth at less than 37 weeks of gestation (RR 0.96,95% CI: 0.90-1.02; I2 = 31%; P = 0.18). Low-dose aspirin was associated with a significant increase in the rates of postpartum hemorrhage (RR 1.32,95% CI: 1.14-1.54; I2 = 0%; P = 0.0003), placental abruption (RR 2.18,95% CI: 1.10-4.32; I2 = 16%; P = 0.02) and cesarean section (RR 1.053, 95% CI: 1.001-1.108; I2 = 0%; P = 0.05) in nulliparous women. We also did not observe a significant effect of low-dose aspirin on the rates of any hypertensive disorder of pregnancy (RR 1.05, 95% CI: 0.96-1.14; I2 = 9%; P = 0.28) or small for gestational age (RR 0.96, 95% CI: 0.91-1.02; I2 = 0%; P = 0.16) in nulliparous women. Funnel plots indicated that no significant publication bias existed in this meta-analysis. Except for preterm birth at less than 34 weeks of gestation, placental abruption and cesarean section, the sensitivity analysis showed similar results, which confirmed the robustness of this meta-analysis.

CONCLUSIONS

Low-dose aspirin might reduce the risk of preterm birth at less than 34 weeks of gestation in nulliparous women. The use of low-dose aspirin in nulliparous women increased the risk of postpartum hemorrhage and might increase the risk of placental abruption and cesarean section.

Hexoprenaline Compared with Atosiban as Tocolytic Treatment for Preterm Labor

Introduction Preterm birth is defined as a live birth before 37 weeks of gestation and is associated with increased neonatal morbidity and mortality. The aim of this study is to compare the efficacy of hexoprenaline and atosiban for short- and long-term tocolysis and their effects on neonatal and maternal outcomes.

Methods This retrospective cohort study included women with threatened preterm labor between 24 + 0 and 34 + 0 weeks of gestation without premature rupture of membranes. The tocolytic efficacy of hexoprenaline and atosiban was compared in women receiving one of the two medications for short- and long-term tocolysis. Continuous variables were compared using t-test or Mann–Whitney U test, as appropriate. Comparison of categorical variables between the two groups was done with χ ² test after Pearsonʼs and Fisherʼs exact test.

Results 761 women were enrolled in this study; 387 women received atosiban and 374 women received hexoprenaline as their primary tocolytic agent. Atosiban showed a higher efficacy as a primary tocolytic agent (p = 0.000) within 48 hours. As regards long-term tocolysis, there were no differences between the treatment groups (p = 0.466). Maternal side effects such as tachycardia (p = 0.018) or palpitations (p = 0.000) occurred more frequently after the administration of hexoprenaline, while there were no differences between the two drugs administered with regard to any other maternal or neonatal outcome parameter.

Conclusion Our retrospective study shows a significantly higher efficacy of atosiban in the first 48 hours, especially when administered at an early gestational age. There were no significant differences in terms of neonatal outcome but significantly more maternal adverse effects during the administration of hexoprenaline.

Pr-AKI: Acute Kidney Injury in Pregnancy – Etiology, Diagnostic Workup, Management

Despite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.