Neonatal sepsis is considered critical for a significant increase in neonatal morbidity and mortality among hospitalized neonates. Neonatal sepsis, in most cases, coexists with coagulopathy, which can prove to be life-threatening. Complex molecular and cellular systems are involved in the cross-talk between inflammation and hemostasis during sepsis. Disturbances in the regulating systems of the vascular endothelium, and platelet–endothelial and platelet–neutrophil interactions play a pivotal role in both inflammation and coagulation. This complex process is poorly understood in neonates. In addition to the developmental maturation of hemostasis and the immune response in neonatal sepsis, a cellular model of hemostasis during sepsis should be taken into account. This review focused on the molecular and cellular mechanisms underlying inflammation and hemostasis during neonatal sepsis, taking the developmental immune response and developmental hemostasis into account in order to provide future diagnostic approaches to be applied in everyday clinical settings. Regarding the diagnostic modalities, we briefly provide the limitations of the currently used conventional coagulation assays, focusing on viscoelastic tests and platelet flow cytometry.

Objectives: Although the vaccination against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS Cov-2) is considered safe during pregnancy, vaccine hesitancy among pregnant women is high. The results of published observational studies addressing the issue of Covid-19 vaccination’s efficacy and safety during pregnancy need to be summarized. Content: This systematic review compares the incidence of major maternal and neonatal outcomes between SARS Cov-2 vaccinated and unvaccinated pregnant women. The included studies enrolled pregnant women of any age and any trimester. Medline-Pubmed, Scopus, Cochrane Library, and grey literature were searched until the 28th of May 2022, and 2,947 studies were found. Summary: Seven observational cohort studies, enrolling 67,274 pregnant women, were selected. When comparing vaccinated and unvaccinated pregnant women, SARS Cov-2 vaccines were not associated with major maternal and neonatal adverse events. The rate of SARS Cov-2 infections among vaccinated pregnant women compared to unvaccinated is significantly reduced by 43%. Outlook: SARS Cov-2 vaccination in pregnant women is effective and safe. The results are promising, but caution is advised due to some limitations: only observational studies addressing this issue were found. Parallelly, the enrolled populations and the intervention (vaccination type and the number of doses) were not homogeneous.

Intraventricular hemorrhage (IVH) is a multifactorial disorder, the most important risk factors of which are prematurity and low birth weight. Disturbances in cerebral blood flow, inherent fragility of the germinal matrix vasculature, and platelet/coagulation disturbances are the 3 major pathogenic mechanisms. In this context, we investigated the role of platelet indices and several maternal and neonatal characteristics in the development of IVH through a retrospective cohort analysis of 130 extremely premature neonates, 24% of whom presented with severe IVH. There was a significant difference in platelet counts between the IVH and the control group on the first day of life (P=0.046). Presence of IVH was linked with lower birth weight (P=0.006) and lower gestational age (P=0.001). Platelet count on the first day of life was positively correlated with survival (P=0.001) and, along with platelet mass, was indicative of the worst IVH grade recorded for each neonate (P=0.002 and 0.007, respectively). Prolonged prothrombin time was also correlated with IVH (P<0.001), but factor analysis supported no prominent role. Maternal medications seem to play a minor role as well. In conclusion, IVH in extremely premature infants cannot be solely explained by platelet parameters, and further studies are required to determine the relationships between IVH, platelet indices, and outcomes.

Neonatal sepsis is frequently accompanied by coagulopathy and thrombocytopenia attributed to the cross-link between inflammation and coagulation. However, sepsis-induced coagulopathy and platelet function in septic preterm neonates remain to be elucidated. In addition, there is no robust evidence for a causal relationship between thrombocytopenia and bleeding in preterm neonates with sepsis. This single-center prospective cohort study aimed to assess sepsis-induced coagulopathy and platelet function in preterm neonates during sepsis. We included 25 preterm neonates with Gram-positive sepsis born at gestational age 24 + 1 to 34 + 3 and studied in comparison to 30 healthy counterparts. Coagulation was assessed using conventional coagulation tests (CCTs) and rotational thromboelastometry (ROTEM). Platelet function was evaluated by flow cytometry. The study was conducted at 3-time points, at 1st, at 2nd to 3rd, and at 5th to 7th day of sepsis, respectively. Compared with healthy controls, neonates with Gram-positive sepsis present in ROTEM a hypercoagulable state; a higher maximum clot firmness (MCF) and higher amplitudes of intrinsic rotational thromboelastometry (INTEM) (INTEM MCF: median, 71; P .004 and INTEM A10: median, 67; P .005, respectively), extrinsic rotational thromboelastometry (EXTEM) (EXTEM MCF: median, 70; P .02 and EXTEM A10: median, 67; P .02, respectively), and rotational thromboelastometry assay for fibrin formation (FIBTEM) (FIBTEM MCF: median, 25; P < .001 and FIBTEM A10: median, 23; P .002, respectively). Conversely, CCTs exhibited hypocoagulation. Thrombocytopenia in preterm neonates with Gram-positive sepsis is not associated with an increased bleeding risk. In Gram-positive sepsis, platelets display increased glycoprotein (GP) surface receptors' expression (GPIb: median, 2.8; P .03, GPIIb: median, 3.1; P .004, and GPIIIa: median, 3.9; P .008, respectively) and reduced activation (P-selectin: median, 1; P < .001). A higher expression of platelets GP and improved degranulation capacity were recorded in patients in higher gestational age groups of >32 weeks of gestation. Platelet GPIb expression is age-dependent in healthy neonates. Neonatal Gram-positive sepsis is characterized by a progressive hypercoagulation along with increased GP expression, reduced platelet activation, and thrombocytopenia without bleeding. Platelet GP expression and degranulation capacity are age-dependent among neonates with sepsis. Platelet GP expression is age-dependent among healthy counterparts.

Pre-eclampsia (PE) is a placenta-mediated disease and remains a major cause of maternal and neonatal mortality and morbidity. As PE develops, normal pregnancy’s hypercoagulable balance is disrupted, leading to platelet hyperactivation, excessive pathological hypercoagulability, and perturbed fibrinolysis. This narrative review aims to summarize the current knowledge regarding hemostasis in PE compared with healthy gestation and the potential effects of maternal PE on neonatal hemostasis. Finally, it aims to discuss hemostasis assessments for normal pregnancies and PE, emphasizing the role of viscoelastic tests, namely, thromboelastography (TEG) and thromboelastometry (ROTEM), for monitoring PE-associated hemostatic alterations. The use of TEG/ROTEM for assessing the hemostatic profile of PE women has been little considered, even though conventional coagulation tests (CCTs) have not helped to monitor hemostasis in this population. Compared with normal pregnancy, TEG/ROTEM in PE reveals an excessive hypercoagulability analogous with the severity of the disease, characterized by higher-stability fibrin clots. The TEG/ROTEM parameters can reflect PE severity and may be used for monitoring and as predictive markers for the disease.