OBJECTIVE: To systematically evaluate the efficacy of low molecular weight heparin (LMWH) to prevent preeclampsia in high risk pregnant women without thrombophilia.
METHODS: PubMed, Embase and the Cochrane library were searched for articles published before 1st August 2022 using the combination keywords \"preeclampsia\", \"Low Molecular Weight Heparin\", \"LMWH\", \"Heparin, Low Molecular Weight\", \"Dalteparin\", \"Nadroparin\", and \"Tinzaparin\".
METHODS: Randomized controlled trials evaluating the use of LMWH in pregnant women at high risk of preeclampsia without thrombophilia.
METHODS: Ten studies were included in the meta-analysis (1758 patients in total). Outcomes were expressed as relative risk (RR) with 95% confidence intervals (CI).
RESULTS: LMWH reduced the incidence of PE (RR = 0.67; 95% CI = 0.50-0.90; P = 0.009) in high risk pregnant women without thrombophilia. Subgroup analysis found that the prophylactic effect of LMWH was only significant in studies using low-dose aspirin (LDA) as the primary intervention. The combination of LMWH and LDA was also effective for the prevention of preterm birth and fetal growth restriction, but had no effect on the incidence of placenta abruption.
CONCLUSIONS: For women at high risk of developing preeclampsia without thrombophilia, the combination of LMWH and low-dose aspirin is effective for the prevention of preeclampsia, preterm birth and fetal growth restriction and is superior to LDA alone.

Recent advances in small-bowel endoscopy such as capsule endoscopy have shown that non-steroidal anti-inflammatory drugs (NSAIDs) frequently damage the small intestine, with the prevalence rate of mucosal breaks of around 50% in chronic users. A significant proportion of patients with NSAIDs-induced enteropathy are asymptomatic, but some patients develop symptomatic or complicated ulcers that need therapeutic intervention. Both inhibition of prostaglandins due to the inhibition of cyclooxygenases and mitochondrial dysfunction secondary to the topical effect of NSAIDs play a crucial role in the early process of injury. As a result, the intestinal barrier function is impaired, which allows enterobacteria to invade the mucosa. Gram-negative bacteria and endogenous molecules coordinate to trigger inflammatory cascades via Toll-like receptor 4 to induce excessive expression of cytokines such as tumor necrosis factor-α and to activate NLRP3 inflammasome, a multiprotein complex that processes pro-interleukin-1β into its mature form. Finally, neutrophils accumulate in the mucosa, resulting in intestinal ulceration. Currently, misoprostol is the only drug that has a proven beneficial effect on bleeding small intestinal ulcers induced by NSAIDs or low-dose aspirin, but its protection is insufficient. Therefore, the efficacy of the combination of misoprostol with other drugs, especially those targeting the innate immune system, should be assessed in the next step.

The aim of the present meta-analysis study was to evaluate the efficacy of low-dose aspirin, commenced at ≤16 weeks of gestation, in preventing preterm and term preeclampsia, as well as associated maternal and neonatal adverse events in women at risk of preeclampsia. The Embase, PubMed, Cochrane Central Register of Controlled Trials and the Web of Science databases were searched for relevant random controlled trials (RCTs) published between January 1979 and October 2017. After quality assessment and data extraction, a meta-analysis was performed using RevMan 5.3 software. Outcomes of interest were preeclampsia with subgroups of preterm preeclampsia (delivery at <37 weeks) and term preeclampsia, as well as maternal adverse outcomes, including gestational hypertension, postpartum hemorrhage and preterm birth, and neonatal adverse outcomes, including intrauterine growth retardation (IUGR) or small for gestation age infant (SGA), stillbirth or death, and newborn weight. A total of 10 RCTs involving 3,168 participants were included. The meta-analysis demonstrated that, compared with placebo or no treatment, low-dose aspirin was associated with a significant reduction in the overall risk ratio (RR) of preeclampsia regardless of the time to delivery [RR=0.67; 95% confidence interval (CI)=0.57-0.80]. This was apparent for preterm preeclampsia (RR=0.35; 95% CI=0.13-0.94) but not for term preeclampsia (RR=1.01; 95% CI=0.60-1.70). Except for postpartum hemorrhage, low-dose aspirin also significantly reduced the risk of maternal and neonatal adverse outcomes. In conclusion, low-dose aspirin in women at risk of preeclampsia, commenced at ≤16 weeks of gestation, was associated with a reduced risk of preterm preeclampsia, and of adverse maternal and neonatal outcomes.

Aspirin is typically discontinued in spinal surgery because of increased risk of hemorrhagic complications. The risk of perioperative continuation of aspirin in neurosurgery needed to be evaluated.
This study aimed to evaluate all available evidence about continuation of aspirin and to compare peri- and postoperative blood loss and complication rates between patients that continued aspirin and those who discontinued aspirin perioperatively in spinal surgery.
Systematic review and meta-analysis were carried out.
A meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies comparing aspirin continuation with discontinuation were included. Studies using a combination of anticlotting agents or non-spinal procedures were excluded. Operative outcomes (blood loss and operative length) and different complications (surgical site infection [SSI]), stroke, myocardial infarction within 30 days postoperatively) were extracted. Overall prevalence and means were calculated for the reported outcomes in fixed-effects models with heterogeneity (I-squared [I2]) and effect modification (P-interaction) assessment.
Out of 1,339 studies, three case series were included in the meta-analysis. No significant differences in mean operating time were seen between the aspirin-continuing group (mean=201.8 minutes, 95% confidence interval [CI]=193.3; 210.3; I2=95.4%; 170 patients) and the aspirin-discontinuing group (mean=178.4 minutes, 95% CI=119.1; 237.6; I2=93.5%; 200 patients); (P-interaction=0.78). No significant differences in mean perioperative blood loss were seen between the aspirin-continuing group (mean=553.9 milliliters, 95% CI=468.0; 639.9; I2=83.4%; 170 patients) and the aspirin-discontinuing group (mean=538.7 milliliters, 95% CI=427.6; 649.8; I2=985.5%; 200 patients); (P-interaction=0.96). Similar non-significant differences between the two groups were found for cardiac events, stroke, and surgical site infections.
This meta-analysis showed an absence of significant differences in perioperative complications between aspirin continuation and discontinuation. Because of the paucity of included studies, further well-designed prospective trials are imperative to demonstrate potential benefit and safety.