The evaluation and management of neonatal coagulation disorders

Hemostatic Profile of Intrauterine Growth-Restricted Neonates: Assessment with the Use of NATEM Assay in Cord Blood Samples

BACKGROUND

Intrauterine growth restriction (IUGR) is associated with hemorrhagic and thrombotic complications during the perinatal period. Thrombocytopenia, platelet dysfunction, and prolonged standard coagulation tests are observed in this population. The aim of this study is to examine the hemostatic profile of IUGR neonates with the use of a non-activated assay (NATEM) in cord blood samples.

METHODS

During an 18 month period, a NATEM ROTEM assay was performed on cord blood samples of 101 IUGR neonates. A total of 189 appropriate for gestational age (AGA) neonates were used as a control group. The NATEM variables recorded include the following: clotting time (CT); clot formation time (CFT); clot amplitude at 5, 10, and 20 min (A5, A10, A20); α-angle (a°); maximum clot firmness (MCF); lysis index at 30 and 60 min (LI30, LI60); and maximum clot elasticity (MCE).

RESULTS

IUGR neonates demonstrate a hypocoagulable state, with lower A5, A10, A2, MCF, and MCE values when compared to AGA. Using multiple linear regression, we determined IUGR as an independent factor influencing all NATEM parameters (except CT and LI30) exhibiting a hypocoagulable and hypofibrinolytic profile. Platelet count was positively correlated with A5, A10, A20, MCF, alpha angle, and MCE, and negatively correlated with CFT.

CONCLUSION

IUGR neonates appear with lower clot strength and elasticity and prolonged clot kinetics, as illustrated by ROTEM variables.

Investigating the Impact on Long-Term Outcomes and the Necessity of Hereditary Thrombophilia Screening in Presumed or Perinatal Arterial Ischemic Stroke

This study aimed to investigate the influence of prothrombotic risk factors on long-term outcomes of patients with perinatal arterial ischemic stroke. The study was conducted through an analysis of monitoring results that were regularly maintained for approximately 20 years at a tertiary stroke-monitoring center. The study assessed prothrombotic risk factors, radiological area of involvement, clinical presentation, treatments, clinical outcomes, and long-term outcomes of the 48 patients included in the study, with a mean monitoring time of 77.6 ± 45.7 months (range: 6-204). Our results showed that the presence of prothrombotic risk factors did not affect long-term outcomes. However, patients with middle cerebral artery infarction had the highest risk of developing cerebral palsy, whereas those with presumed stroke had the highest risk of developing epilepsy. This study suggests that prothrombotic risk factors should not be evaluated during the acute stage unless there is a strong suspicion of the patient's history, and prevention or early diagnosis of presumed stroke patients will positively impact their long-term prognosis.

A Global Assessment of Coagulation Profile and a Novel Insight into Adamts-13 Implication in Neonatal Sepsis

Neonatal sepsis is a life-threatening condition associated with significant morbidity and mortality. Sepsis-induced coagulopathy is a well-recognized entity, signifying the strong cross-talk between inflammation and coagulation. The aim of the present study was to compare the coagulation profile between the acute phase of sepsis and recovery in term and preterm neonates. Additional comparisons to healthy neonates were undertaken. Levels of clotting, anti-clotting factors and ADAMTS-13 (A disintegrin and metalloprotease with thrombospondin type-1 motives), the cleaving protein of von Willebrand factor (VWF), were measured in 16 term and preterm neonates in the acute phase of infection and following recovery, as well as in 18 healthy neonates. Clotting times were prolonged, while levels of particular clotting factors were lower in the acute phase of infection compared to controls and recovery. On the other hand, levels of fibrinogen, factor VIII (FVIII) and VWF were significantly higher in the acute phase in comparison to controls and recovery, while they remained persistently higher in the infection group compared to controls. In regard to the anticlotting mechanism, a clear suppression was observed in septic neonates. ADAMTS-13 levels were significantly lower in the acute phase of infection in comparison to controls and recovery (p = 0.015 and 0.004, respectively), while a trend toward superimposed normalization was demonstrated post infection, as higher ADAMTS-13 levels were measured in recovered neonates compared to controls (p = 0.002). The coagulation profile is considerably deranged in neonatal sepsis. ADAMTS-13 deficiency in septic neonates is a novel finding with promising future implications, as ADAMTS-13 substitution may serve as a useful therapeutic option in neonatal sepsis, prompting further investigation in future studies.

Fresh frozen plasma and cryoprecipitate: Can we safely reduce their use in the NICU?

OBJECTIVE

To study patterns of use of Fresh Frozen Plasma (FFP) and Cryoprecipitate (CRYO) in a level 4 NICU and assess what proportions were not supported by literature.

STUDY DESIGN

single centered retrospective observational. Charts of neonates admitted between 1/1/2010 to 12/31/2017 to CT Children's level 4 NICU were reviewed. Transfusions were assigned as "supported" or "non-supported" based on available evidence. Groups were compared using T-tests and chi-squared analyses.

RESULTS

of 4110 total admissions, 197 (4.8%) received a total of 461 transfusions (374 FFP, 87 CRYO). Only 59% of FFP and 60% CRYO were supported by literature. Within the "non-supported" group the largest category was neonates transfused prophylactically.

CONCLUSION

A large proportion of transfusions administered to neonates was not evidence-based, suggesting there are opportunities for improvement in use of these products.

Reference Values of Thromboelastometry Parameters in Healthy Term Neonates Using NATEM in Cord Blood Samples

Background: ROTEM assay has gained increasing acceptance as a method for rapid and specific coagulation pathway assessment. However, its use in the neonatal population remains limited since reference ranges have not yet been established. Aims: (1) to determine reference ranges for healthy term neonates of ROTEM parameters using non-activated assay (NATEM) in cord blood samples; (2) to assess whether delivery mode, gender, gestational age, birth weight and blood group (ABO and Rhesus) of the neonate, coagulation disorder and anticoagulant medication of the mother have an impact on NATEM parameters. Methods: NATEM assay was conducted in cord blood samples of 189 term neonates without any medical history. Results: Reference ranges (2.5th and 97.5th percentiles) are established for clotting time (CT), clot formation time (CFT), α-angle, clot amplitude at 5, 10 and 20 min (A5, A10, A20), maximum clot firmness (MCF), lysis index at 30 and 60 min (LI30, LI60, %) and maximum clot elasticity (MCE). Reference ranges for NATEM are CT 182-499 s, CFT 63-176 s, α-angle 58-78°, A5 28-52 mm, A10 37-61 mm, A20 42-66 mm, MCF 43-67 mm, LI30 97-100%, LI60 87-98% and MCE 75-203. Male neonates appear to be more hypocoagulable than females. Conclusions: We demonstrate reference ranges for healthy term neonates in NATEM assay that could be used as a reference group for future studies of neonates with an underlying pathology.

Venous Thromboembolism in Premature Neonates

While the incidence of venous thromboembolism (VTE) is lower among children than adults, the newborn period is one of two bimodal peaks (along with adolescence) in VTE incidence in the pediatric population. Most VTE cases in neonates occur among critically ill neonates being managed in the neonatal intensive care unit, and most of these children are born premature. For this reason, the presentation, diagnosis, management, and outcomes of VTE among children born premature deserve special emphasis by pediatric hematologists, neonatologists, pharmacists, and other pediatric health care providers, as well as by the scientific community, and are described in this review.

Pentoxifylline in the treatment of neonatal vasospasm and thromboembolism: An observational case series study

WHAT IS KNOWN AND OBJECTIVE

Newborns, particularly preterm babies, are prone to vascular vasospasm and thromboembolism. Differences in the haemostatic system, small vessel diameter and presence of any serious diseases are predisposing causes of thromboembolic disease in newborns. The lack of randomized controlled studies on the management of vasospasm and thromboembolism exacerbates the problem. We present a case series of the successful and safe use of PTX for the treatment of vasospasm and thrombosis in neonates.

METHODS

The study was conducted in the Bezmialem Vakif University Hospital Neonatal Intensive Care Unit (NICU). A retrospective chart review was performed on consecutive patients treated for vascular spasm and thrombosis. Nine patients diagnosed with vasospasm or thrombosis were enrolled in the study.

RESULTS

Five patients had arterial injuries. Six patients were premature, and five patients were diagnosed with thrombosis by using Doppler ultrasonography (US). The drug was diluted with 5% dextrose and administered intravenously at a dose of 5 mg/kg/h over six hours, ranging from 1 to 5 days. No drug-related side effects were observed. All babies recovered, and no amputation was performed.

WHAT IS NEW AND CONCLUSION

PTX may be an alternative treatment for vascular vasospasm and thromboembolism with fewer side effects than anticoagulant and thrombolytic agents in neonates. Starting PTX in the early stages of vascular insult may prevent the development of vasospasm and thromboembolism and thus limb ischaemia.

Iatrogenic vs. Spontaneous Preterm Birth: A Retrospective Study of Neonatal Outcome Among Very Preterm Infants

Objective: Preterm birth is a leading contributor to childhood morbidity and mortality, and the incidence tends to increase and is higher in developing countries. The aim of this study was to analyze the potential impact of preterm birth in different etiology groups on neonatal complications and outcomes and to gain insight into preventive strategies.

Methods: We performed a retrospective cohort study of preterm infants less than 32 weeks' gestation in the Third Affiliated Hospital of Zhengzhou University from 2014 to 2019. Preterm births were categorized as spontaneous or iatrogenic, and these groups were compared for maternal and neonatal characteristics, neonatal complications, and outcomes. All infants surviving at discharge were followed up at 12 months of corrected age to compare the neurodevelopmental outcomes.

Results: A total of 1,415 mothers and 1,689 neonates were included, and the preterm population consisted of 1,038 spontaneous preterm infants and 651 iatrogenic preterm infants. There was a significant difference in the incidence of small for gestational age between the two groups. Infants born following spontaneous labor presented with a higher risk of intraventricular hemorrhage, whereas iatrogenic preterm birth was associated with higher risk of necrotizing enterocolitis and coagulopathy and higher risk of pathoglycemia. There was no difference in mortality between the two groups. Follow-up data were available for 1,114 infants, and no differences in neurologic outcomes were observed between the two preterm birth subtypes.

Conclusions: Preterm births with different etiologies were associated with some neonatal complications, but not with neurodevelopmental outcomes at 12 months of corrected age.

Dual mutation (MTHFR A1298C with PAI (4G) mutation) manifesting with bilateral lower limb gangrene in a neonate

Neonates are at highest risk of thrombosis among paediatric patients. The relative prothrombotic state in a well neonate is compensated by other factors preventing spontaneous thrombosis; however, in a neonate with genetic predisposition, the balance is tilted predisposing them to a life-threatening thrombotic episode. We describe a rare case of methylenetetrahydrofolate reductase A1298C (homozygous) mutation along with plasminogen activator inhibitor (4G) mutation in a neonate who developed bilateral lower limb gangrene following thrombosis of the iliac vessels without any triggering factor. The neonate underwent thrombectomy as debulking measure along with thrombolytic therapy followed by unfractionated heparin and low-molecular-weight heparin which is still being continued along with oral aspirin. The neonate had to undergo amputation of both the involved lower limbs in view of dry gangrene. This case highlights that the dual mutations causing the prothrombotic state predispose the individual to the spontaneous life-threatening thrombotic episode as compared with the single mutation.

Thrombocytopenia in Neonates

Thrombocytopenia defined as platelet count below 150,000/μL is not an uncommon event at the neonatal intensive care unit (NICU). In our region we calculated a prevalence of nearly 2 of 1000 live births. Early-onset neonatal thrombocytopenia (NT) occurring within the first 72 hours of life is more common than late-onset NT. Preterm infants are affected more often than term infants and bacterial infection is the most common diagnosis associated with NT. There are a lot of maternal, perinatal, and neonatal causes associated with NT and complications include bleedings with potentially life-threatening intracranial hemorrhage. Alloimmune thrombocytopenia (NAIT) often presents with severe thrombocytopenia (<30,000/μL) in otherwise healthy newborns and needs careful evaluation regarding HPA-1a antigen status and HLA typing. Platelet transfusions are needed in severe NT and threshold platelet counts might be at ≤25,000/μL irrespective of bleeding or not. Immune mediated NT recovers within 2 weeks with a good prognosis when there happened no intracranial hemorrhage. This short review gives an overview on etiology and causes of NT and recommendations regarding platelet transfusions.

Thromboelastographic profiles of healthy very low birthweight infants serially during their first month

OBJECTIVE

We determined thromboelastographic (TEG) profiles of healthy very low birthweight infants (VLBWIs) of the day of birth and at set intervals during their first month.

DESIGN

Prospective observational study with blinded clinical and laboratory follow-up.

SETTING

Level III neonatal intensive care unit (June 2015 to June 2018).

PATIENTS

Consecutive qualifying VLBWIs were enrolled at birth and followed up for 30 days.

INTERVENTIONS AND MAIN OUTCOMES MEASURES

Laboratory (citrated-native TEG, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, blood count) and clinical variables were retrieved at birth, 3rd-5th, 10th and 30th day of life. Blood samples temporally related to events with a potential hemostatic impact (sepsis, bleeding, platelets/plasma transfusions, ibuprofen/indomethacin administration) were excluded from analysis.

RESULTS

We enrolled 201 VLBWIs and 72 full-term neonates. Sixty-seven of the healthy VLBWIs completed the 30-day follow-up. 541 TEG traces were analysed.On day 1, the median (minimum-maximum) TEG values were as follows: reaction time (R), 8.2 min (1-21.8); kinetics (K), 2.8 min (0.8-16); α angle, 51° (14.2-80.6); maximum amplitude (MA), 54.9 mm (23.9-76.8). PT and APTT were 15.9 s (11.7-51.2) and 59 s (37.8-97.5), respectively. The above parameters suggest minor hypocoagulability compared with term infants. On day 30, the median (minimum-maximum) R was 5 (1-16.9), K 1 (0.8-4.1), α 74.7 (41.1-86.7) and MA 70.2 (35.8-79.7). PT and APTT were 12.1 (10.4-16.6) and 38.8 (29.6-51.4), respectively. Those parameters are consistent with a relatively hypercoagulable phenotype, compared with term infants.

CONCLUSIONS

Healthy VLBWIs have a prolonged PT and APTT, but their TEG profiles suggest a relatively balanced hemostatic system, with slight hypocoagulability initially (compared with term neonates), gradually evolving to a somewhat more procoagulant phenotype over the first month.

Epidemiology of thrombosis in Canadian neonatal intensive care units

OBJECTIVE

To assess the rate, location, risk factors, management, and outcomes of neonatal thrombosis (NT).

DESIGN

A retrospective study investigating infants admitted to NICUs in Canadian Neonatal Network between January 2014 and December 2016 and diagnosed with NT. Each infant with NT was matched with an infant without NT.

RESULTS

Of 39,971 infants, 587 (1.5%) were diagnosed with NT: 440 (75%) venous, 112 (19%) arterial, 29 (5%) both. NT rate was 1.4% in full-term and 1.7% in preterm infants. Venous thrombi occurred most commonly in the portal vein and arterial thrombi in the cerebral artery. Conservative management and low molecular weight heparin were the most common treatment modalities. Hospital stay was longer (p < 0.001) in the NT patients, but mortality was similar.

CONCLUSIONS

NT was diagnosed in ~15/1000 NICU admissions and most commonly in the portal vein and cerebral arteries. Management varied based on the type and location of thrombi. Large multicenter trials are needed to address the best management strategies.

Arterial ischemic stroke (AIS) in childhood: clinical report from a single control center

INTRODUCTION

Stroke is the clinical designation for a rapidly developing loss of brain function due to an interruption in the blood supply to all or part of the brain. It is the third cause of death in adults and one of the top 10 causes in pediatric age. The perinatal period of onset is the second only to adult age group in the incidence of stroke. Arterial ischemic stroke during childhood occurs most frequently in the perinatal period with an incidence of 1 out 2300-5000 live infant births.

MATERIALS AND METHODS

This is a retrospective study that includes 28 patients affected by perinatal arterial ischemic stroke. Family and gestational history, risk factors of perinatal stroke, gender and clinical data of affected children and outcome are reported.

RESULTS

A stroke family history was registered in three unrelated families. Gestational history disclosed cases of threats of abortion, preterm delivery, hyperthermia, gestosis, and placental disorders. In the children, onset of seizures were reported within 3 days of life and diagnosis of stroke was confirmed by brain MRI which disclosed involvement of the middle cerebral artery in all the cases. Hemilateral cerebral palsy, epileptic seizures, and intellectual disability from mild to severe were the most frequent complications.

CONCLUSION

Stroke is still a common and dreadful events in perinatal period as this disorder is often unpredictable and cause of severe neurological impairment.

Thrombocytopenia as one of the reasons of prolonged stay in the Neonatal intensive care unit

The aim of this paper was to present the occurrence and severity of thrombocytopenia, with intracranial and another bleeding in neonates with sepsis, analyze the risk factors for the development of thrombocytopenia and compare it with the length of hospitalization in the Neonatal Intensive Care Unit (NICU). Thrombocytopenia is a platelet count <150 x 109/L and is common in newborns during hospitalization in the NICU. In the early days of life, the most common causes of thrombocytopenia in newborns are conditions that lead to fetal hypoxia, intrauterine growth failure, maternal hypertension, and sepsis. In this study were included all newborns with thrombocytopenia, who were hospitalized in NICU, Children's Disease Clinic, University Clinical Centre in Tuzla, from 01. 01. 2014 to 01. 01. 2019. In our results, 379 newborns had severe, 337 moderate, and 127 milder forms of thrombocytopenia, without a statistically significant difference in the incidence of thrombocytopenia between groups of neonates born < 37 GW and 37 GW. Sepsis was the most common cause of thrombocytopenia, 300 children had early sepsis and 190 late. We found the statistically significant difference in intracranial hemorrhage of the second degree and pulmonary hemorrhage among neonates born < 37 GW in relation to newborns born 37 GW. A statistically significant effect of length of stay of our neonates in the Department of Neonatal Intensive Therapy and morbidity was shown in relation to the lower gestational age and lower platelet counts. Conclusion: Timely diagnosis of the cause and development of thrombocytopenia with adequate and effective treatment can reduce the mortality and morbidity of newborns with perinatal risk for neonatal thrombocytopenia.

[Spontaneous neonatal aortic thrombosis revealing protein S deficiency]

Arterial thrombosis of the newborn is rare and associated with poor prognosis, often attributed to umbilical arterial catheterization. The aortic and spontaneous forms are exceptional. Its severity requires fast and effective treatment. Although therapeutic means are numerous, no consensus has been established to date although thrombolysis and heparin therapy appear to give good results depending on the site and extent of thrombosis. We report a case of extensive thrombosis of the abdominal aorta in a 5-day-old newborn, revealed by acute hypernatremic dehydration. Thrombosis was not related to umbilical catheterization. The diagnosis was confirmed by Doppler ultrasound with discovery during the etiologic assessment of an authentic protein S deficiency. This observation was the occasion for a review of the literature concerning the evolutionary and therapeutic clinical aspects of neonatal arterial thrombosis.

Neonatal thrombocytopenia-causes and outcomes following platelet transfusions

We evaluated the causes for neonatal thrombocytopenia (NT), the duration of NT, and the indications of platelet transfusions (PT) by means of a retrospective cohort study over a 23-year period. Neonates with NT were identified via ICD-10 code D69.6. Of 371 neonates (1.8/1000 live births) with NT, the majority (312; 84.1%) had early onset thrombocytopenia, and 282 (76%) were preterm born. The most frequent causes for NT were early and late onset sepsis and asphyxia. The mean duration of thrombocytopenia was 10.2 days and was negatively correlated (KK = - 0.35) with the number of PT. PT were given to 78 (21%) neonates, 38 (49%) of whom had very severe NT. The duration of NT was positively related to the severity of NT and the number of subsequent PT. A mortality rate of 10.8% was significantly associated with bleeding signs (p < 0.05) and correlated with increasing number of PT (p < 0.05) but not with the severity of NT (p = 0.4). In the case of relevant hemorrhage, PT did not influence the mortality rate (p = 0.09). All deaths followed neonatal sepsis.

CONCLUSIONS

Prematurity and diagnoses including early and late onset sepsis and asphyxia were the most common causes of NT. Mortality was not associated with the severity of NT but increased with the number of PT. What is Known: • The causes for neonatal thrombocytopenia (NT) are well known. • The effects of platelet transfusions (PT) and its indications are still a matter of debate and recommendations differ widely. What is New: • The duration of NT is positively related to the severity of NT and the number of subsequent PT. • The mortality rate is not associated with the severity of NT but increases with increasing numbers of PT and in the case of relevant intraventricular hemorrhage (≥ grade II), PT does not influence the mortality rate.

Reference ranges of thromboelastometry in healthy full-term and pre-term neonates

Background:

Rotational thromboelastometry (ROTEM) is an attractive method for rapid evaluation of hemostasis in neonates. Currently, no reference values exist for ROTEM assays in full-term and pre-term neonates. Our aim was to establish reference ranges for standard extrinsically activated ROTEM assay (EXTEM) in arterial blood samples of healthy full-term and pre-term neonates.

Methods:

In the present study, EXTEM assay was performed in 198 full-term (≥37 weeks’ gestation) and 84 pre-term infants (<37 weeks’ gestation) using peripheral arterial whole blood samples.

Results:

Median values and reference ranges (2.5th and 97.5th percentiles) for the following main parameters of EXTEM assay were determined in full-term infants: clotting time (seconds), 41 (range, 25.9–78); clot formation time (seconds), 70 (range, 40–165.2); maximum clot firmness (mm), 66 (range, 41–84.1); lysis index at 60 min (LI60, %), 97 (range, 85–100). The only parameter with a statistically significant difference between full-term and pre-term neonates was LI60 (p=0.006). Furthermore, it was inversely correlated with gestational age (p=0.002) and birth weight (p=0.016) in pre-term neonates.

Conclusions:

In conclusion, an enhanced fibrinolytic activity in pre-term neonates was noted. For most EXTEM assay parameters, reference ranges obtained from arterial newborn blood samples were comparable with the respective values from studies using cord blood. Modified reagents, small size samples, timing of sampling, and different kind of samples might account for any discrepancies among similar studies. Reference values hereby provided can be used in future studies.

Assessment of Functional Fibrinolysis in Cord Blood Using Modified Thromboelastography

BACKGROUND

The fibrinolytic system in newborns is immature and probably impaired. The aim of this study was to prospectively evaluate functional fibrinolytic capacity of newborn's cord blood using a new thromboelastometry (rotational thromboelastogram, ROTEM®) test.

METHODS

Infants born at Sheba Medical Center were studied prospectively. Cord blood was obtained immediately after clumping, and ROTEM parameters were assessed applying non-activated TEM (NATEM) assay with increasing concentration of tissue plasminogen activator (tPA, 0-200 U/ml). Baseline clotting time (CT), clot formation time (CFT), alpha angle, and maximum clot firmness (MCF) were compared among infants versus adults. Each infant's demographic information was prospectively followed up until discharge.

RESULTS

One hundred one newborns were tested. CT and CFT values were lower and alpha angles were higher among neonate's cord blood compared to adults (n = 23; P = 0.001, 0.03, and 0.02, respectively). The addition of tPA significantly shortened CT and CFT, and reduced alpha angles and MCF in both groups. The lysis index at 30 min (LI30) and lysis onset time (LOT) decreased significantly, and fibrinolysis was more rapid in the newborns. Hematocrit and platelet counts in neonates correlated with LI30 (P = 0.035 and 0.037, respectively) and LOT (P = 0.02) when higher tPA concentrations were used. ROTEM values were unrelated to the occurrence of postnatal complications.

CONCLUSIONS

This first report of functional fibrinolysis in cord blood demonstrated that neonatal fibrinolysis may be augmented as compared to adult values. Further studies are required to validate this test and assess its predictive value and clinical relevance.

Clinical Data of Neonatal Systemic Thrombosis

OBJECTIVE

To evaluate clinical data and associated risk conditions of noncerebral systemic venous thromboembolism (VT), arterial thromboembolism (AT), and intracardiac thromboembolism (ICT) in neonates.

STUDY DESIGN

Data analysis of first systemic thromboembolism occurring in 75 live neonates (0-28 days), enrolled in the Italian Registry of Pediatric Thrombosis from neonatology centers between January 2007 and July 2013.

RESULTS

Among 75 events, 41 (55%) were VT, 22 (29%) AT, and 12 (16%) ICT; males represented 65%, and 71% were preterm. In 19 (25%), thromboembolism was diagnosed on the first day of life. In this "early onset" group, prenatal-associated risk conditions (maternal/placental disease) were reported in 70% and inherited thrombophilia in 33%. Postnatal risk factors were present in 73%; infections and central vascular catheters in 56% and 54% VT, respectively, and in 67% ICT vs 27% AT (<.05). Overall mortality rate was 15% and significant thromboembolism-related sequelae were reported in 16% of discharged patients.

CONCLUSIONS

This report from the Registro Italiano Trombosi Infantili, although limited by representing an uncontrolled case series, can be used to develop future clinical trials on appropriate management and prevention of neonatal thrombosis, focusing on obstetrical surveillance and monitoring of critically ill neonates with vascular access. A thrombosis risk prediction rule specific for the neonatal population should be developed through prospective controlled studies.

Maternal rare inherited bleeding disorders and neonatal complications

AIM

The aim of this study was to examine the association between maternal inherited bleeding disorders and neonatal complications.

MATERIAL AND METHODS

This was a historical cohort study. The rare inherited bleeding disorders (RIBD) group consisted of a total of 100 women suffering from inherited bleeding disorders, aged 20-45 years who experienced pregnancy. In the healthy control group, 200 age- and body mass index-matched women were selected. Details of demographic and obstetric characteristics of the samples in both groups were collected using their medical records.

RESULTS

The mean ages of the women in the RIBD and healthy control groups were 32.6 (7.07) and 32.4 (7.3) years, respectively. No statistically significant differences were found in terms of age and other demographic characteristics of the women between the groups. The mean neonatal birthweight in the RIBD group was statistically lower than that in the healthy control group, 3018.2 (546.9) g vs. 3299.4 (456.8) g, respectively (P = 0.021). The prevalence of low birthweight in the RIBD group was statistically higher in comparison to that in the healthy control group (P = 0.041). After adjustment for potential confounders, it was found that maternal bleeding disorder had significant negative effects on birthweight in newborns (odds ratio, 1.05; 95% confidence interval, 1.01-3.43, P = 0.001). Those infants were statistically more likely to experience head bleeding, early hyperbilirubinemia and hospitalization than the healthy group (P = 0.001).

CONCLUSIONS

Maternal rare inherited bleeding disorders may have a devastating consequence for neonates.

Thrombosis in the Neonatal Intensive Care Unit

Neonates have the highest risk for pathologic thrombosis among pediatric patients. A combination of genetic and acquired risk factors significantly contributes to this risk, with the most important risk factor being the use of central venous catheters. Proper imaging is critical for confirming the diagnosis. Despite a significant number of these events being life- and limb-threatening, there is limited evidence on what the appropriate management strategy should be. Evaluation and treatment of any neonate with a clinically significant thrombosis should occur at a tertiary referral center that has proper support.

Interpretation of clotting tests in the neonate

There are significant differences between the coagulation system in neonates compared with children and adults. Abnormalities of standard coagulation tests are common within the neonatal population. The laboratory tests of activated partial thromboplastin time (aPTT) and prothrombin time (PT) were developed to investigate coagulation factor deficiencies in patients with a known bleeding history, and their significance and applied clinical value in predicting bleeding (or thrombotic) risk in critically ill patients is weak. Routine screening of coagulation on admission to the neonatal intensive care unit leads to increased use of plasma for transfusion. Fresh frozen plasma (FFP) is a human donor plasma frozen within a short specified time period after collection (often 8 h) and then stored at -30°C. FFP has little effect on correcting abnormal coagulation tests when mild and moderate abnormalities of PT are documented in neonates. There is little evidence of effectiveness of FFP in neonates. A large trial by the Northern Neonatal Nursing Initiative assessed the use of prophylactic FFP in preterm infants and reported no improvement in clinical outcomes in terms of mortality or severe disability. An appropriate FFP transfusion strategy in neonates should be one that emphasises the therapeutic use in the face of bleeding rather than prophylactic use in association with abnormalities of standard coagulation tests that have very limited predictive value for bleeding.

Developmental hemostasis: clinical implications from the fetus to the adolescent

The coagulation system involves a dynamic group of procoagulation and anticoagulation proteins that appear early in fetal life and whose levels change throughout childhood and into the teenage years. This process is called developmental hemostasis. Developmental hemostasis creates unique challenges for clinicians affecting the diagnosis and treatment of coagulation disorders during early childhood. The objective of this review is to assist pediatricians in understanding the coagulation system in fetal life and childhood and to provide guidance for interpreting basic coagulation testing, which will result in an improved ability to diagnose and treat patients with hemostatic and thrombotic disorders.

Multifocal haemorrhagic brain damage following hypoxia and blood pressure lability: case report and rat model

AIMS

Haemorrhagic brain damage is frequently encountered as a complication of premature birth. Much less frequently, multifocal petechial haemorrhage is identified in asphyxiated term newborns. Our goal was to develop an experimental rat model to reproduce this pattern of brain damage.

METHODS

Neonatal rat pups were exposed to a 24-h period of 10% or 8% hypoxia followed by a single dose of phenylephrine. Acute and subacute changes, as well as long-term outcomes, were investigated by histology, brain magnetic resonance imaging and behavioural assessment. Immunostaining for vascular endothelial growth factor and caveolin-1 was performed in the rat brains as well as in a 17-day human case.

RESULTS

Small foci of haemorrhage were identified in almost all regions of the rat brain subjected to hypoxia plus phenylephrine, but not hypoxia alone. Exposure to 8% hypoxia was associated with more haemorrhagic foci than 10% hypoxia. With rare exceptions, the blood deposits were too small to be detected by magnetic resonance imaging. Altered immunohistochemical detection of vascular endothelial growth factor and caveolin-1 in the child and the rat model suggests a role for blood-brain barrier compromise. There were no clear behavioural changes and no residual morphological abnormalities in the 78-day follow-up of the rats.

CONCLUSIONS

We conclude that transient hypoxia, in a dose-dependent manner, can weaken the vasculature and predispose to brain haemorrhage in the situation of labile blood pressure. Persistent hypoxia is likely to be important in the genesis of permanent severe brain damage.

Restrictive guideline reduces platelet count thresholds for transfusions in very low birth weight preterm infants

BACKGROUND AND OBJECTIVES

Platelet transfusions are performed almost entirely according to expert experience. This study assessed the effectiveness of a restrictive guideline to reduce platelet transfusions in preterm infants.

METHODS

A retrospective cohort of preterm infants with a birth weight of <1500 g had been born in 2 periods. In Period 1, a transfusion was indicated for a platelet count of <50,000/ml in clinically stable neonates or <100,000/ml in bleeding or clinically unstable infants. In Period 2, the indications were restricted to <25,000/ml in clinically stable neonates, or <50,000/ml in newborns who were either on mechanical ventilation, subject to imminent invasive procedures, within 72 h following a seizure, or extremely premature and <7 days old. A count of <100,000/ml was indicated for bleeding or major surgery.

RESULTS

Periods 1 and 2 comprised 121 and 134 neonates, respectively. The rates of ventricular haemorrhage and intrahospital death were similar in both periods. The percentage of transfused infants, the odds of receiving a platelet transfusion, the mean platelet count before transfusion and the percentage of transfusions with a platelet count >50,000/ml were greater in Period 1. Among thrombocytopenic neonates, the percentage of transfused neonates and the number of transfusions were similar in both groups.

CONCLUSION

The restrictive guideline for platelet transfusions reduced the platelet count thresholds for neonatal transfusions without increasing the rate of ventricular haemorrhage.

Heparin infusion to prevent umbilical venous catheter related thrombosis in neonates

OBJECTIVE

To investigate umbilical venous catheter (UVC) related thrombosis by Doppler echocardiographic evaluation of neonates infused with heparin or placebo.

METHODS

We conducted a prospective study to determine UVC-related thrombosis in term and nearterm neonates. Heparin or placebo (0.5 IU/mL) was infused at a rate of 1 mL/hr to the study and control group. Doppler echocardiography was performed at 1, 3, and 5 days after UVC insertion.

RESULTS

Forty-six neonates (63% males) with a mean gestational age of 38.2 ± 1.8 weeks, and a mean birth-weight of 2993 ± 563 grams were included. No UVC-related thrombosis was observed in the study group, which included 19 neonates. Among the 27 neonates in the control group, one neonate developed UVC-related thrombosis. There were no statistical differences between the groups for gestational age, birth weight, postnatal age, UVC duration, mortality, mechanical ventilation, and inotrope requirement, and hemagram or coagulation profile. The complications were as follows, mild pulmonary hemorrhage, 6.5% (3); leak-out, 4.3% (2); peritoneal leakage, 2.2% (1); occlusion, 2.2% (1); gastrointestinal findings, 6.5% (3); sepsis, 10.9% (5); and catheter-related thrombosis, 2.2% (1).

CONCLUSION

This study demonstrated that heparin infusion of 0.5 IU/mL through the UVC had no effect on catheter-related thrombosis in term and near-term neonates. Randomized controlled trials are necessary to conclusively evaluate the effect of heparin on UVC-related thrombosis.

Management of neonatal thrombosis

Neonates have one of the highest risks for thromboembolism among pediatric patients. This risk is attributable to a combination of multiple genetic and acquired risk factors. Despite a significant number of these events being either life threatening or limb threatening, there is limited evidence on appropriate management strategy. Most of what is recommended is based on uncontrolled studies, case series, or expert opinion. This review begins with a discussion of the neonatal hemostatic system, focusing on the common sites and imaging modalities for the detection of neonatal thrombosis. Perinatal and postnatal risk factors are presented and management options discussed.

Protein C deficiency: a case review

Protein C (PC) deficiency is a rare but life-threatening bleeding disorder that can present in the immediate neonatal period. This article presents the case of a baby girl with acute and progressive neonatal purpura fulminans as the presenting feature of PC deficiency. Other common complications of this disease include ophthalmic problems and central nervous system (CNS) changes. Management consists of correcting the coagulopathy, intensive wound care including negative-pressure dressings and skin grafting, and supportive care for the ophthalmic and CNS issues. Long-term follow-up consists of lifelong anticoagulant therapy to avoid recurrence of these complications.

Effects of in vitro adult platelet transfusions on neonatal hemostasis

BACKGROUND

Thrombocytopenia is frequent among neonates, and 20-25% of affected infants are treated with platelet transfusions. These are frequently given for mild thrombocytopenia (platelets: 50-100 × 10(9) L(-1)), largely because of the known hyporeactivity of neonatal platelets. In tests of primary hemostasis, however, neonates have shorter bleeding and closure times (CTs) than adults. This has been attributed to their higher hematocrits, higher von Willebrand factor (VWF) concentrations, and predominance of longer VWF polymers.

OBJECTIVE

To determine whether the 'transfusion' of adult (relatively hyperreactive) platelets into neonatal blood results in a hypercoagulable profile.

METHODS

Cord blood (CB) and adult peripheral blood (PB) were separated (with a modified buffy coat method) to generate miniaturized platelet concentrates (PCs) and thrombocytopenic blood. PB-derived and CB-derived PCs (n = 7 per group) were then 'transfused'in vitro into thrombocytopenic CB and PB. The effects of autologous vs. allogeneic (developmentally mismatched) 'transfusions' were evaluated with whole blood aggregometry, a platelet function analyzer (PFA-100), and thromboelastography (TEG).

RESULTS

Adult platelets aggregated significantly better than neonatal platelets in response to thrombin receptor-activating peptide, ADP, and collagen, regardless of the blood into which they were transfused. The 'transfusion' of adult platelets into thrombocytopenic CB resulted in shorter CTs-EPI (PFA-100) and higher clot strength and firmness (TEG) than 'transfusion' of neonatal autologous platelets.

CONCLUSIONS

In vitro'transfusion' of adult platelets into neonatal blood results in shorter CTs than 'transfusion' with neonatal platelets. Our findings should raise awareness of the differences between the neonatal and adult hemostatic system and the potential 'developmental mismatch' associated with platelet transfusions for neonatal hemostasis.

Platelet transfusion in the neonatal intensive care unit: benefits, risks, alternatives

Platelet transfusions were introduced into clinical medicine about 60 years ago when they were shown to reduce the mortality rate of patients with leukemia who were bleeding secondary to hyporegenerative thrombocytopenia. In modern neonatology units, platelet transfusions are integral and indeed lifesaving for some neonates. However, the great majority of platelet transfusions currently administered in neonatal intensive care units (NICUs) are not given in the original paradigm to treat thrombocytopenic hemorrhage, but instead are administered prophylactically with the hope that they will reduce the risk of spontaneous bleeding. Weighing the risks and benefits of platelet transfusion, although imprecise, should be attempted each time a platelet transfusion is ordered. Adopting guidelines specific for platelet transfusion will improve consistency of care and will also generally reduce transfusion usage, thereby reducing costs and conserving valuable blood bank resources. Initiating specific programs to improve compliance with transfusion guidelines can further improve NICU transfusion practice.

Etiology and treatment of perinatal stroke; a role for prothrombotic coagulation factors?

The detection rate of perinatal stroke is rising due to improved neuroradiological imaging techniques, increased survival of neonates with severe underlying diseases and an increased awareness of the diagnosis by pediatricians. Its pathogenesis is multifactorial and includes a large variety of maternal and neonatal risk factors as well as prothrombotic coagulation factors. Although the relative risk of prothrombotic coagulation factors is still unknown, testing is recommended to design large studies in the near future. This article is an overview of studies of prothrombotic risk factors in both neonatal arterial ischemic stroke and cerebral sinovenous thrombosis. Although prothrombotic coagulation factors are present in more than half of the cases, we conclude that they most likely play a minor role in the pathogenesis of perinatal stroke. Current therapeutic guidelines focusing on thrombosis are based on expert opinion and recommend low molecular weight or unfractionated heparin for cardioembolic arterial ischemic stroke, antiplatelet or anticoagulant therapy for recurrent arterial ischemic stroke, and low molecular weight heparin or unfractionated heparin for sinovenous thrombosis without hemorrhage and/or when extension of the thrombotic process occurs.

The evaluation and management of postnatal thromboses

In the pediatric population, neonates have the highest risk for thromboembolism (TE), most likely due to the frequent use of intravascular catheters. This increased risk is attributed to multiple risk factors. Randomized clinical trials dealing with management of postnatal thromboses do not exist, thus, opinions differ regarding optimal diagnostic and therapeutic interventions. This review begins with an actual case study illustrating the complexity and severity of these types of cases, and then evaluates the neonatal hemostatic system with discussion of the common sites of postnatal thrombosis, perinatal and prothrombotic risk factors, and potential treatment options. A proposed step-wise evaluation of neonates with symptomatic postnatal thromboses will be suggested, as well as future research and registry directions. Owing to the complexity of ischemic perinatal stroke, this topic will not be reviewed.