How I manage neonatal thrombocytopenia

Egyptian Pediatric Guidelines for the Management of Children with Isolated Thrombocytopenia Using the Adapted ADAPTE Methodology-A Limited-Resource Country Perspective

BACKGROUND

Thrombocytopenia is a prevalent presentation in childhood with a broad spectrum of etiologies, associated findings, and clinical outcomes. Establishing the cause of thrombocytopenia and its proper management have obvious clinical repercussions but may be challenging. This article provides an adaptation of the high-quality Clinical Practice Guidelines (CPGs) of pediatric thrombocytopenia management to suit Egypt's health care context.

METHODS

The Adapted ADAPTE methodology was used to identify the high-quality CPGs published between 2010 and 2020. An expert panel screened, assessed and reviewed the CPGs and formulated the adapted consensus recommendations based on the best available evidence.

DISCUSSION

The final CPG document provides consensus recommendations and implementation tools on the management of isolated thrombocytopenia in children and adolescents in Egypt. There is a scarcity of evidence to support recommendations for various management protocols. In general, complete clinical assessment, full blood count, and expert analysis of the peripheral blood smear are indicated at initial diagnosis to confirm a bleeding disorder, exclude secondary causes of thrombocytopenia and choose the type of work up required. The International Society of Hemostasis and thrombosis-Bleeding assessment tool (ISTH-SCC BAT) could be used for initial screening of bleeding manifestations. The diagnosis of immune thrombocytopenic purpura (ITP) is based principally on the exclusion of other causes of isolated thrombocytopenia. Future research should report the outcome of this adapted guideline and include cost-analysis evaluations.

The Prevalence and Associated Risk Factors for Neonatal Thrombocytopenia Among Newborns Admitted to the Neonatal Intensive Care Unit

Background Thrombocytopenia is the most prevalent hematological condition in neonates that develops in the neonatal intensive care unit (NICU). This set of illnesses is caused by either decreased platelet production due to placental insufficiency, increased platelet breakdown (consumption), or a combination of the two causes. Based on platelet count, it is defined as mild, moderate, or severe thrombocytopenia, with early and late onset. Purpose The purpose of this study is to determine the prevalence of thrombocytopenia and the factors that contribute to it in newborns hospitalized in the neonatal critical care unit at the Maternity and Children Hospital in Al Ahsa, Saudi Arabia. Methods This descriptive retrospective cross-sectional study was carried out at the NICU of the Maternity and Children Hospital in Al Ahsa, Saudi Arabia, over the span of one year (August 2022 to August 2023) among hospitalized neonates with thrombocytopenia. Thrombocytopenia is defined as a platelet count of 150,000 or less. These patients were monitored until they recovered or died. Results The inclusion criteria were met by a total of 242 newborns with thrombocytopenia. Half of the neonates (57%) were full-term, with Apgar scores greater than 5 at the first (84%) and fifth (93%) minutes, respectively. The great majority of individuals (84%) experienced early-onset thrombocytopenia of mild severity (62%) and were asymptomatic (93%). The majority of the cases resolved spontaneously, with only 21% requiring platelet transfusion. There was a significant relationship discovered between gestational age and the severity of thrombocytopenia, with very preterm infants having moderate to severe thrombocytopenia, as well as birth weight (p=0.001). Furthermore, neonates with severe thrombocytopenia had a considerably higher mortality rate (p=0.001). Conclusion The mortality and morbidity of newborns with perinatal risk for neonatal thrombocytopenia can be reduced with timely detection of the cause and development of thrombocytopenia, as well as adequate and early care.

Thrombocytopenia and neonatal outcomes among extremely premature infants exposed to maternal hypertension

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are associated with neonatal hematological disturbances, such as thrombocytopenia. The association of HDP to platelet counts in the context of extreme prematurity, to trends of platelet counts during neonatal hospitalization, and to frequency of platelet transfusions remain to be explored.

PROCEDURE

Retrospective study of infants born at less than 29 weeks born between 2015 and 2019. Platelet counts were collected on initial complete blood count, at 2 weeks, 32 weeks post-menstrual age (PMA), 36 weeks PMA, and closest to discharge. We examined the association between HDP and platelet counts at each time point, frequency of platelet transfusions and intraventricular hemorrhage (IVH) grade 3 or more.

RESULTS

Total 296 infants were included, 43 exposed to HDP. Infants exposed had lower platelet counts at each time point, as well as a higher prevalence of platelet less than 150 × 10⁹ /L on one of the time points (32% vs. 65%, p < .001). Infants exposed to maternal hypertension were more frequently exposed to platelet transfusions (63% vs. 18%, p < .001). Mixed effect model demonstrated an association between HDP and a lower trend in platelet counts at each time point (β = -94 × 10³ /μl, p < .001). Although initial platelet count was associated with severe IVH, it was not associated to exposure to HDP.

CONCLUSION

Premature infants exposed to HDP have a higher prevalence of thrombocytopenia, increased frequency of platelet transfusion, and an altered trend in platelet counts during neonatal hospitalization.

Neonatal reticulocytes among preterm infants of small for gestational age

BACKGROUND

We previously reported that higher reticulocyte counts were observed in earlier preterm infants. Here we present an additional study that focused on reticulocyte counts among preterm infants of small for gestational age (SGA). To assess the relationship between SGA and perinatal variables during the early postnatal period.

METHODS

A single-center study was undertaken at Ohta Nishinouchi Hospital between April 1, 2016 and June 30, 2021, using blood samples prospectively collected from infants admitted to the neonatal intensive care unit. These were assessed by univariate analysis and multivariate logistic regression analysis.

RESULTS

A total of 467 preterm infants were analyzed, 367 (78.6%) non-SGA and 100 (21.4%) SGA. The median [interquartile range (IQR)] GA (weeks) for the two groups was 33 (31-35) and 34 (31-36), respectively (p = 0.058). The median (IQR) BW (g) for the two groups was 1888 (1480 to 2195) and 1381 (1019 to 1782), respectively (p < 0.001). There were significant relationships between SGA and BW (p < 0.001, OR, 0.997; 95% CI, 0.996 to 0.998), umbilical artery pH (p = 0.038, OR, 0.031; 95% CI, 0.010 to 0.827), Apgar at 5 min (p < 0.001, OR, 1.816; 95% CI, 1.301 to 2.536), nucleated erythrocyte count (p = 0.027, OR, 1.013; 95% CI, 1.001 to 1.024), reticulocyte count (p < 0.001, OR, 0.992; 95% CI, 0.988 to 0.995) and chorioamnionitis (p = 0.019, OR, 0.427; 95% CI, 0.210 to 0.868).

CONCLUSION

These results suggest that preterm infants with SGA adapted more rapidly to the postnatal environment than did non-SGA preterm infants. Moreover, a lower reticulocyte count among preterm infants born SGA may be an indicator of good adaptation to the extra-uterine environment during the early postnatal period.

Cerebral vasculature exhibits dose-dependent sensitivity to thrombocytopenia that is limited to fetal/neonatal life

Whether increasing platelet counts in fetal and neonatal alloimmune thrombocytopenia (FNAIT) is effective at preventing intra-cerebral hemorrhage (ICH) has been a subject of debate. The crux has been whether thrombocytopenia is the major driver of ICH in diseases such as FNAIT. We recently demonstrated in mice that severe thrombocytopenia was sufficient to drive intra-cerebral hemorrhage in utero and in early neonatal life. It remains unclear what degree of thrombocytopenia is required to drive ICH and for how long after birth thrombocytopenia can cause ICH. By inducing a thrombocytopenic range, we demonstrate that there is a large buffer-zone of mild thrombocytopenia that does not result in ICH, that ICH becomes probabilistic at 40% of normal platelet numbers, and that ICH becomes fully penetrant below 10% of normal platelet number. We also demonstrate that although the neonatal mouse is susceptible to thrombocytopenia-induced ICH, this sensitivity is rapidly lost between post-natal days 7 - 14. These findings provide important insights into the risk of in utero ICH with varying degrees of thrombocytopenia and into defining the developmental high-risk period for thrombocytopenia-driven ICH in a mouse model of FNAIT.

Establishing reference ranges of cord blood: point-of-care hemostatic function assessment in preterm and term neonates

BACKGROUND

Thrombelastometry, allowing timely assessment of global hemostatic function, is increasingly used to guide hemostatic interventions in bleeding patients. Reference values are available for adults and children, including infants but not neonates immediately after birth.

METHODS

Neonates were grouped as preterm (30 + 0 to 36 + 6 weeks/days) and term (37 + 0 to 39 + 6 weeks/days). Blood samples were drawn from the umbilical cord immediately after cesarean section and analyzed by thrombelastometry. Reference ranges were determined for the extrinsic and intrinsic coagulation pathways, fibrin polymerization, and hyperfibrinolysis detection.

RESULTS

All extrinsically activated test parameters, but maximum lysis (P = 0.139) differed significantly between both groups (P ≤ 0.001). Maximum clot firmness in the fibrin polymerization test was comparable (P = 0.141). All intrinsically activated test parameters other than coagulation time (P = 0.537) and maximum lysis (P = 0.888) differed significantly (P < 0.001), and so did all aprotinin-related test parameters (P ≤ 0.001) but maximum lysis (P = 0.851).

CONCLUSIONS

This is the first study to identify reference ranges for thrombelastometry in preterm and term neonates immediately after birth. We also report differences in clot initiation and clot strength in neonates born <37 versus ≤40 weeks of gestation, mirroring developmental hemostasis.

IMPACT

Impact: This prospective observational study is the first to present reference ranges in preterm and term infants for all types of commercially available tests of thrombelastometry, notably also including the fibrin polymerization test.

IMPORTANCE

Viscoelastic coagulation assays such as thrombelastometry have become integral to the management of perioperative bleeding by present-day standards. Reference values are available for adults, children, and infants but not for neonates. Key message: Clot initiation and formation was faster and clot strength higher in the term than in the preterm group. Parameters of thrombelastometry obtained from cord blood do not apply interchangeably to preterm and term neonates.

Fetale und neonatale Alloimmunthrombozytopenie, Teil 2

Die fetale und neonatale Alloimmunthrombozytopenie (FNAIT) wird durch mütterliche Antikörper hervorgerufen, die gegen ein vom Vater ererbtes Blutgruppenmerkmal an fetalen Thrombozyten gerichtet sind. Während Teil 1 des Beitrags Ausgabe die Ätiologie, die Pathogenese und die Diagnostik der FNAIT thematisiert hatte, widmet sich dieser 2. Teil der Risikostratifizierung und Behandlung 1.

Platelet Counts and Patent Ductus Arteriosus in Preterm Infants: An Updated Systematic Review and Meta-Analysis

Background: A meta-analysis published in 2015 showed a significant association between low platelet counts in the first day(s) of life and risk of patent ductus arteriosus (PDA). The meta-analysis pooled data from 11 studies cohorts (3,479 preterm infants). Objective: To update the meta-analysis by adding new studies on the topic and including other platelet parameters different from platelet counts. Methods: PubMed/Medline and Embase databases were searched. Random-effects risk ratios (RR) and differences in means (DM) and 95% confidence intervals (CI) were calculated. Results: We included 31 studies (7,638 infants). Meta-analysis showed that the risk of developing any PDA was significantly associated with platelet counts<150 × 109/L (11 studies, RR 1.58, 95% CI 1.28 to 1.95), and <100 x 109/L (7 studies, RR 1.61, 95% CI 1.14 to 2.28), but not <50 x 109/L (4 studies, RR 1.34, 95% CI 0.77 to 2.32). Risk of developing hemodynamically significant PDA (hsPDA) was significantly associated with platelet counts<150 x 109/L (12 studies, RR 1.33, 95% CI 1.09 to 1.63), and <100 x 109/L (7 studies, RR 1.39, 95% CI 1.06 to 1.82), but not <50 x 109/L (6 studies, RR 1.24, 95% CI 0.86 to 1.79). Infants with hsPDA had significantly lower mean platelet counts (19 studies, DM 22.0 x 109, 95% CI 14.9 to 29.1) and platelet mass (11 studies, DM 214.4, 95% CI 131.2 to 297.5) and significantly higher platelet distribution width (PDW, 9 studies, DM -0.53, 95% CI -1.01 to -0.05) than infants without hsPDA. Meta-analysis could not demonstrate significant differences in mean platelet volume (MPV). Conclusion: Compared to the previous analysis, this updated meta-analysis included 21 additional studies that provide stronger evidence of the association between low platelet counts and PDA/hsPDA. Other platelet parameters such as platelet mass and PDW are also associated with hsPDA risk. However, the low number of platelets may be an epiphenomenon associated with the maturity and clinical stability of preterm infants rather than a contributing factor in the pathogenesis of PDA.

Risk factors for severity of thrombocytopenia in full term infants: a single center study

Background

Neonatal thrombocytopenia (NT) (platelet count < 150 × 10⁹/L) is a common finding in the neonatal intensive care unit (NICU). The main aim of this study was to assess the prevalence, risk factors, and outcomes of severe NT in full term (FT) infants.

Methods

During the study period, all FT infants who met the inclusion criteria for NT on two occasions were included. Maternal data, such as maternal age, weight, gestational age, mode of delivery, and history of systemic diseases, including diabetes mellitus, pre-eclampsia, systemic lupus erythematosus, and immune thrombocytopenic purpura, were recorded. Furthermore, neonatal data, such as gender, neonatal weight, causes/duration of admission, types of respiratory support used, complete blood count measurements, and outcomes for neonates admitted to the NICU, were recorded.

Results

In total, 55 FT infants with NT met the inclusion criteria, and 29 (52.73%) cases had severe NT. The most common cause of NT was neonatal sepsis (20 cases, 36.35%), followed by a postoperative state (5 cases, 9.09%). Moreover, in cases of positive blood cultures, the most commonly isolated organism was Escherichia coli (6 cases, 10.90%), followed by Klebsiella (5 cases, 9.09%). Cases of severe NT needed more platelet transfusions (P = 0.001) and had higher rates of mortality (P = 0.001) when compared to cases of mild/moderate NT associated with signs of bleeding and pulmonary/intraventricular hemorrhage (IVH) (P = 0.001).

Conclusion

Severe NT compared to mild/moderate NT, associated with signs of bleeding and pulmonary/IVH, needed more platelet transfusions, and had increased mortality. Further research is needed to explain which of these complications related to severity of thrombocytopenia or were associated with original disease of the babies.

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.

The role of ROTEM variables based on clot elasticity and platelet component in predicting bleeding risk in thrombocytopenic critically ill neonates

BACKGROUND

Our aim was to investigate the role of thromboelastometry (ROTEM) parameters, including maximum clot elasticity (MCE) and platelet component (PLTEM MCE and PLTEM MCF), in early prediction of bleeding events in thrombocytopenic critically ill neonates.

MATERIAL AND METHODS

This single-center, prospective cohort study included 110 consecutive thrombocytopenic neonates with sepsis, suspected sepsis, or hypoxia. On the first day of disease onset, ROTEM EXTEM and FIBTEM assays were performed and the neonatal bleeding assessment tool was used for the evaluation of bleeding events.

RESULTS

Most EXTEM and FIBTEM ROTEM parameters significantly differed between neonates with (n = 77) and without bleeding events (n = 33). Neonates with bleeding events had significantly lower PLTEM MCE and PLTEM MCF values compared to those without bleeding events (P < .001). Platelet count was found to be strongly positively correlated with EXTEM A5 (Spearman's rho = 0.61, P < .001) and A10 (rho = 0.64, P < .001). EXTEM A10 demonstrated the best prognostic performance (AUC = 0.853) with an optimal cutoff value (≤37 mm) (sensitivity = 91%, specificity = 76%) for prediction of bleeding events in thrombocytopenic neonates.

CONCLUSIONS

EXTEM A5 and EXTEM A10 were found to be strong predictors of hemorrhage, compared to most ROTEM variables quantifying clot elasticity and platelet component in thrombocytopenic critically ill neonates.

A Newborn With Skin Lesions, Thrombocytopenia, and Gastrointestinal Bleeding

A term infant girl was admitted for evaluation of severe thrombocytopenia. She also had purpura-like skin lesions. A complete blood count showed a platelet count of 40×10/L (normal value: 150 to 400×10/L). She received random donor platelet transfusions and intravenous immunoglobulin therapy; however, thrombocytopenia persisted. She developed bloody stools on day 5 of life and hematemesis on day 9. Upper gastrointestinal endoscopy revealed multiple small, 2 to 5 mm, vascular lesions throughout the stomach body and proximal duodenum. Our multidisciplinary team will discuss an approach towards a term infant with thrombocytopenia and gastrointestinal bleeding, the diagnostic challenges, and patient management.

Transfusion support: Considerations in pediatric populations

Over 400,000 units of blood and blood products are transfused to pediatric patients annually, yet only sparse high-quality data exist to guide the preparation and administration of blood products in this population. The direct application of data from studies in adult patients should be undertaken with caution, as there are dissimilarities in the pathology and physiology between adult and pediatric patients. We provide an overview of available evidence in the field of pediatric transfusion medicine, summarizing indications for blood product transfusion, thresholds for transfusion and indications for blood product modifications.

An infant with refractory cytomegalovirus-induced thrombocytopenia

The present case underscores the importance of considering the association of severe thrombocytopenia or immune thrombocytopenia with cytomegalovirus (CMV) infection because CMV-induced thrombocytopenia occasionally requires antiviral therapy.

Severe thrombocytopenia in pregnancy: a case series from west China

Thrombocytopenia is the second most common hematological disease during pregnancy and is mainly caused by gestational thrombocytopenia, immune thrombocytopenia, or preeclampsia/HELLP syndrome. This study aims to investigate the causes and pregnancy outcomes of thrombocytopenia in pregnancies with platelet counts below 50 × 10⁹/L. We retrospectively analyzed the pregnancies diagnosed with severe thrombocytopenia at a tertiary care center in western China between January 2009 and December 2017. All enrolled pregnancies were divided into three groups according to the lowest platelet counts: group A (30-50 × 10⁹/L), group B (10-30 × 10⁹/L), and group C (< 10 × 10⁹/L). Maternal and fetal outcomes were observed and compared among these three platelet levels. A total of 533 consecutive pregnancies were included. A relatively large proportion (37.3%, 199/533) of them showed a history of thrombocytopenia before pregnancy or during a previous pregnancy. Most of the women (70.2%, 374/533) received corticosteroids, intravenous immunoglobulin, or platelet transfusion treatments. The incidence of preterm birth < 37 weeks (26.3%, 15/57), cesarean section (93%, 53/57), and neonatal intensive care unit (NICU) admission (31.6%, 18/57) occurred significantly more often in group C than in groups A and B. Neonatal platelet counts were detected in 28.2% of the infants (155/549), and neonatal thrombocytopenia was found in 40.6% of the infants (63/155). Intracranial hemorrhage occurred in 0.9% of the neonates (5/549) throughout the study period, with neonatal nadir platelet counts between 20 × 10⁹/L and 245 × 10⁹/L. One perinatal death occurred in group C. Pregnancies with the lowest platelet counts below 10 × 10⁹/L are more often complicated by preterm birth, cesarean section, and NICU admission compared with those lowest platelet counts 30-50 × 10⁹/L and 10-30 × 10⁹/L. Neonatal intracranial hemorrhage was uncommon in pregnancies with severe thrombocytopenia. Active management should be performed to avoid possible preterm birth and neonatal NICU admission in pregnancies with the lowest platelet counts below 10 × 10⁹/L.

Fetal and neonatal alloimmune thrombocytopenia: recommendations for evidence-based practice, an international approach

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) may result in severe bleeding, particularly fetal and neonatal intracranial haemorrhage (ICH). As a result, FNAIT requires prompt identification and treatment; subsequent pregnancies need close surveillance and management. An international panel convened to develop evidence-based recommendations for diagnosis and management of FNAIT. A rigorous approach was used to search, review and develop recommendations from published data for: antenatal management, postnatal management, diagnostic testing and universal screening. To confirm FNAIT, fetal human platelet antigen (HPA) typing, using non-invasive methods if quality-assured, should be performed during pregnancy when the father is unknown, unavailable for testing or heterozygous for the implicated antigen. Women with a previous child with an ICH related to FNAIT should be offered intravenous immunoglobulin (IVIG) infusions during subsequent affected pregnancies as early as 12 weeks gestation. Ideally, HPA-selected platelets should be available at delivery for potentially affected infants and used to increase the neonatal platelet count as needed. If HPA-selected platelets are not immediately available, unselected platelets should be transfused. FNAIT studies that optimize antenatal and postnatal management, develop risk stratification algorithms to guide management and standardize laboratory testing to identify high risk pregnancies are needed.

Management of neonatal thrombocytopenia in a context of maternal antiplatelet alloimmunization: Expert opinion of the French-speaking working group

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a potentially devastating disease, seen in 1/800-1000 neonates. FNAIT is the most common cause of early-onset isolated severe neonatal thrombocytopenia in maternity wards. The most feared complication of this disorder is intracranial hemorrhage, leading to death or neurological sequelae. There is no systematic screening of at-risk pregnancies and FNAIT is often discovered when fetal or neonatal bleeding is observed. A working group on fetomaternal platelet alloimmunization was created in 2017, under the auspices on the French Group of Thrombosis and Hemostasis (GFHT). The first objective of this group was to survey clinical practices for treatment of thrombocytopenic neonates in a context of suspected or confirmed FNAIT.

A Prospective Study on the Incidence and Outcomes of Neonatal Thrombocytopenia at a Tertiary Care Facility in Central Saudi Arabia

Background:

The incidence of neonatal thrombocytopenia is low, yet highly dependent on the populations studied.

Purpose:

To assess the incidence of neonatal thrombocytopenia and identify factors associated with its outcomes, namely time to disease onset, recovery duration, and platelet count.

Methods:

A prospective observational study was conducted between May and October 2013 at a large tertiary care facility in Saudi Arabia. Neonates with a platelet count of fewer than 150,000/μL of blood were followed up until their recovery or death.

Results:

The period incidence of neonatal thrombocytopenia was 84/4379 (1.9%). The mortality rate associated with the condition was 68/100,000 births. The male-female ratio of neonates with thrombocytopenia was 2.4:1. The mean (standard deviation) time to disease onset was 1.83 (1.29) days, whereas that of recovery duration was 15.35 (18.46) days. The mean (standard deviation) platelet count at onset was 109,543 (32,826)/μL of blood, whereas that of the increase in platelet count from onset to recovery was 121,876 (78,218)/μL of blood. Treatment comprised monitoring/spontaneous recovery (n = 52, 64.2%) or platelet transfusion (n = 9, 11.1%), immunoglobulins (n = 8, 9.9%), or a combination of both (n = 12, 14.8%). Neonates with a higher gestational age (β = 8061, t = 2.456) and late disease onset (β = 26,178, t = 3.969) were more likely to have a larger increase in platelet count from onset to recovery than those with a lower gestational age (adjusted P = .017) and earlier disease onset (adjusted P < .001).

Implications:

The high incidence of neonatal thrombocytopenia in this Middle Eastern setting indicates that it may be dependent on the population studied. Special attention should be focused on neonates of lower gestational ages and with an early disease onset, because their platelet count recovery may be slower than that of the countergroup.

Intracranial Hemorrhage and Autoimmune Thrombocytopenia in a Neonate: A Rare "Unpredictable" Event

Neonatal thrombocytopenia is a rare complication of maternal autoimmune thrombocytopenia, and no maternal predictors of its gravity and potential complications have been identified. Neonatal cerebral hemorrhage, a feared event in the setting of autoimmune thrombocytopenia, is fortunately uncommon, but it can occur in utero or in the perinatal period, with potentially serious consequences. The authors report the case of a boy born to a mother affected by autoimmune thrombocytopenia, who presented with severe thrombocytopenia at birth and developed intracranial hemorrhage despite mild maternal thrombocytopenia at delivery and a prompt preventive treatment of the newborn. Platelet count should be tested at birth in all babies born from mothers with autoimmune thrombocytopenia, irrespective of maternal platelets counts during pregnancy or at delivery, and should be closely monitored during the first days of life. Systematic early and serial cranial ultrasound might be advocated in the setting of neonatal thrombocytopenia.

My patient is thrombocytopenic! Is (s)he? Why? And what shall I do?

Solving the riddle of a thrombocytopenic patient is a difficult and fascinating task. The spectrum of possible aetiologies is wide, ranging from an in vitro artefact to severe treatment-resistant thrombocytopenic bleeding conditions, or even life-threatening prothrombotic states. Moreover, thrombocytopenia by itself does not protect from thrombosis and sometimes a patient with a low platelet count requires concomitant antithrombotic treatment as well. In order to identify and treat the cause and the effects of the thrombocytopenia, you have to put together several pieces of information, solving a unique jig-jaw puzzle.

The present work is not a textbook article about thrombocytopenia, rather a collection of differential diagnostic thoughts, treatment concepts, and some basic knowledge, that you can retrieve when facing your next thrombocytopenic patient. Enjoy reading it, but most importantly enjoy taking care of patients with a low platelet count. I bet the present work will assist you in this challenging and rewarding clinical task.

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.

Fetal and neonatal alloimmune thrombocytopenia: evidence based antenatal and postnatal management strategies

INTRODUCTION

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a relatively rare but potentially lethal disease, leading to severe bleeding complications in 1 in 11.000 newborns. It is the leading cause of thrombocytopenia in healthy term-born neonates. Areas covered: This review summarizes the antenatal as well as postnatal treatment, thus creating a complete overview of all possible management strategies for FNAIT. Expert commentary: The optimal antenatal therapy in order to prevent bleeding complications in pregnancies complicated by FNAIT is non-invasive treatment with weekly intravenous immunoglobulin (IVIG). Based on risk stratification, weekly doses of IVIG of 0.5 or 1.0g/kg should be administered started early in the second in high risk cases or at the end of the second trimester in low risk cases. The optimal postnatal treatment depends on the platelet count and the clinical condition of the newborn. Prompt administration of compatible platelet transfusion is the first treatment of choice in case of severe thrombocytopenia or active bleeding. In case matched platelets are not directly available, random platelets can also be administered initially to gain time until matched platelets are available. In case of persistent thrombocytopenia despite transfusions, IVIG 1.0-2.0g/kg can be administered.

Bleeding Disorders in Congenital Syndromes

Pediatricians provide a medical home for children with congenital syndromes who often need complex multidisciplinary care. There are some syndromes associated with thrombocytopenia, inherited platelet disorders, factor deficiencies, connective tissue disorders, and vascular abnormalities, which pose a real risk of bleeding in affected children associated with trauma or surgeries. The risk of bleeding is not often an obvious feature of the syndrome and not well documented in the literature. This makes it especially hard for pediatricians who may care for a handful of children with these rare congenital syndromes in their lifetime. This review provides an overview of the etiology of bleeding in the different congenital syndromes along with a concise review of the hematologic and nonhematologic clinical manifestations. It also highlights the need and timing of diagnostic evaluation to uncover the bleeding risk in these syndromes emphasizing a primary care approach.

Neonatal Thrombocytopenia as a Consequence of Maternal Preeclampsia

Introduction Preeclampsia (preE) is pregnancy-induced hypertension affecting a significant proportion of pregnant women worldwide and can cause detrimental effects in the mother and newborn. Some of the effects in the newborn include neonatal thrombocytopenia. Pertaining specifically to neonatal thrombocytopenia, several questions remain unanswered. Discussion According to the current literature, neonatal thrombocytopenia due to maternal preE is highly prevalent in the general population and the incidence is reported to be around 30% worldwide. This review gives an insight into the syndrome and summarizes the possible pathological mechanisms, the diagnostic approach, complications, and therapeutic interventions of neonatal thrombocytopenia. It also identifies the involvement of other cell lines, apart from platelets in the newborns. Furthermore, we suggest a future prospective study to investigate the pathogenesis of preE and plan a study involving animal models to come up with a possible therapeutic intervention to prevent preE and its various consequences in neonates.

Congenital and acquired bleeding disorders in infancy

The diagnosis of congenital and acquired bleeding disorders in infants requires an understanding of developmental haemostasis and the effect on laboratory testing. A systematic approach to bleeding in neonates will aid clinicians in the diagnosis and treatment, which may be caused by a wide variety of diseases. The clinical setting will help to direct the diagnostic pathway. This review will focus on the presentation and diagnosis of congenital and acquired bleeding disorders, including platelet disorders. Current research in this field is ongoing, including investigation into neonatal platelets and their different functionalities, platelet transfusion thresholds and how changes in coagulation factors may be linked to other homeostatic mechanisms.

Neonatal Thrombocytopenia: Etiology and Diagnosis

Neonatal thrombocytopenia has a broad range of possible etiologies. In this review, an asymptomatic newborn infant was found to have severe thrombocytopenia on laboratory testing for limited sepsis evaluation. The differential diagnosis for thrombocytopenia in the newborn period is discussed, along with recommendations for initial evaluation and follow up of isolated thrombocytopenia in an otherwise well-appearing infant. The clinician should be aware of findings associated with unusual causes of thrombocytopenia that should prompt additional evaluation in the nursery or in the general pediatrician's office. In this illustrative case, a high index of suspicion allowed early diagnosis of Wiskott-Aldrich syndrome and prompt curative therapy by stem cell transplant.

Platelets and platelet alloantigens: Lessons from human patients and animal models of fetal and neonatal alloimmune thrombocytopenia

Platelets play critical roles in hemostasis and thrombosis. Emerging evidence indicates that they are versatile cells and also involved in many other physiological processes and disease states. Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a life threatening bleeding disorder caused by fetal platelet destruction by maternal alloantibodies developed during pregnancy. Gene polymorphisms cause platelet surface protein incompatibilities between mother and fetus, and ultimately lead to maternal alloimmunization. FNAIT is the most common cause of intracranial hemorrhage in full-term infants and can also lead to intrauterine growth retardation and miscarriage. Proper diagnosis, prevention and treatment of FNAIT is challenging due to insufficient knowledge of the disease and a lack of routine screening as well as its frequent occurrence in first pregnancies. Given the ethical difficulties in performing basic research on human fetuses and neonates, animal models are essential to improve our understanding of the pathogenesis and treatment of FNAIT. The aim of this review is to provide an overview on platelets, hemostasis and thrombocytopenia with a focus on the advancements made in FNAIT by utilizing animal models.

Neonatal thrombocytopenia and platelet transfusion - a UK perspective

Five percent of newborn infants admitted to UK neonatal units during a recent study developed a platelet count <60 × 10(9)/l, and 60% of these were transfused platelets. This review summarises the common causes and mechanisms of thrombocytopenia in the newborn. Relevant evidence relating the platelet count to the risk of haemorrhage is reviewed, and current UK guidance on transfusion thresholds outlined. The UK policy for the provision of platelets for transfusion to neonates is described, including the particular requirements for neonatal allo-immune thrombocytopenia. Finally, we look towards the future and prospects for reducing the need to expose newborns to donor-derived platelets.

Platelet Counts and Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-Analysis

BACKGROUND

Several cohort studies have shown an association between low platelet counts in the first day(s) of life and patent ductus arteriosus (PDA) in preterm infants. However, these results have not been confirmed by other studies.

OBJECTIVE

To perform a meta-analysis of all the studies addressing the relationship between platelet counts in the first day(s) of life and PDA in preterm infants.

METHODS

PubMed/MEDLINE and EMBASE were searched from their inception until December 2014. Results from 11 cohort studies involving 3,479 preterm infants (gestational age <32 weeks) were pooled using random-effects modeling.

RESULTS

Meta-analysis showed a significant positive association between PDA and platelet counts <150 × 10(9)/l [6 studies, risk ratio (RR) = 1.215, 95% CI: 1.027-1.436], between PDA and platelet counts <100 × 10(9)/l (5 studies, RR = 1.255, 95% CI: 1.034-1.525), and between significant PDA (SPDA) and platelet counts <100 × 10(9)/l (5 studies, RR = 1.254, 95% CI: 1.021-1.540). The association between SPDA and platelet counts <150 × 10(9)/l was not statistically significant (6 studies, RR = 1.289, 95% CI: 0.925-1.795). Pooled standard differences in mean platelet counts between infants with and without PDA/SPDA were not statistically different.

CONCLUSION

This meta-analysis reveals a marginal but significant association between low platelet counts in the first day(s) of life and PDA/SPDA in very preterm infants. This association needs to be confirmed in prospective studies.

Placental pathology and neonatal thrombocytopenia: lesion type is associated with increased risk

OBJECTIVE

To investigate the association between thrombocytopenia and placental lesions.

STUDY DESIGN

Cases included singleton infants admitted to the intensive care unit (2005 to 2010) with platelet counts <100 000 μl(-1). We selected a contemporaneous control group matched for gestational age: 49 cases and 63 controls. The frequency of thrombosis in fetal vessels, fetal thrombotic vasculopathy, acute chorioamnionitis, chronic villitis, infarcts, hematomas, cord insertion and increased circulating nucleated red blood cells were identified on retrospective review of placental histology. Logistic regression models were used to test for associations.

RESULT

Placental lesions associated with poor maternal perfusion (odds ratio (OR) 3.36, 95% confidence interval (CI) 1.38, 8.15) or affecting fetal vasculature (OR 2.75, 95% CI 1.05, 7.23), but not inflammation, were associated with thrombocytopenia. A Pearson Chi-Square Test for Independence for fetal and maternal lesions indicated that the two are independent factors.

CONCLUSION

Poor maternal perfusion and fetal vascular lesions are independently associated with thrombocytopenia in the newborn.

Neonatal thrombocytopenia: etiology, management and outcome

Thrombocytopenia is a very common hematological abnormality found in newborns, especially in preterm neonates. Two subgroups can be distinguished: early thrombocytopenia, occurring within the first 72 hours of life, and late thrombocytopenia, occurring after the first 72 hours of life. Early thrombocytopenia is associated with intrauterine growth restriction, whereas late thrombocytopenia is caused mainly by sepsis and necrotizing enterocolitis (NEC). Platelet transfusions are the hallmark of the treatment of neonatal thrombocytopenia. Most of these transfusions are prophylactic, which means they are given in the absence of bleeding. However, the efficacy of these transfusions in preventing bleeding has never been proven. In addition, risks of platelet transfusion seem to be more pronounced in preterm neonates. Because of lack of data, platelet transfusion guidelines differ widely between countries. This review summarizes the current understanding of etiology and management of neonatal thrombocytopenia.

Neonatal transfusion

Neonates and particularly preterm neonates are frequent recipients of large volumes of blood products relative to their size. Good quality evidence for transfusion practice in this patient group has been lacking but is now increasing. Triggers for red cell transfusion are now better defined, with on-going trials of platelet transfusions likely to yield similar evidence. Transfusion is now extremely safe, but complications such as transfusion associated acute lung injury (TRALI) and transfusion associated circulatory overload (TACO) are likely to be under recognised, particularly in the sick extremely preterm neonate with respiratory symptoms. This review summarises the rationale and current practice with regard to blood component therapy. Background data on component specifications and hazards of transfusion are provided. Indications for transfusion of specific products including red cells, platelets, and plasma are discussed, and their use is illustrated by case examples.

GATA1-mutant clones are frequent and often unsuspected in babies with Down syndrome: identification of a population at risk of leukemia

Transient abnormal myelopoiesis (TAM), a preleukemic disorder unique to neonates with Down syndrome (DS), may transform to childhood acute myeloid leukemia (ML-DS). Acquired GATA1 mutations are present in both TAM and ML-DS. Current definitions of TAM specify neither the percentage of blasts nor the role of GATA1 mutation analysis. To define TAM, we prospectively analyzed clinical findings, blood counts and smears, and GATA1 mutation status in 200 DS neonates. All DS neonates had multiple blood count and smear abnormalities. Surprisingly, 195 of 200 (97.5%) had circulating blasts. GATA1 mutations were detected by Sanger sequencing/denaturing high performance liquid chromatography (Ss/DHPLC) in 17 of 200 (8.5%), all with blasts >10%. Furthermore low-abundance GATA1 mutant clones were detected by targeted next-generation resequencing (NGS) in 18 of 88 (20.4%; sensitivity ∼0.3%) DS neonates without Ss/DHPLC-detectable GATA1 mutations. No clinical or hematologic features distinguished these 18 neonates. We suggest the term "silent TAM" for neonates with DS with GATA1 mutations detectable only by NGS. To identify all babies at risk of ML-DS, we suggest GATA1 mutation and blood count and smear analyses should be performed in DS neonates. Ss/DPHLC can be used for initial screening, but where GATA1 mutations are undetectable by Ss/DHPLC, NGS-based methods can identify neonates with small GATA1 mutant clones.

Distinct differences in platelet production and function between neonates and adults: implications for platelet transfusion practice

Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Among neonates, preterm infants are the subgroup at highest risk for thrombocytopenia and hemorrhage, which is frequently intracranial. Although there is no evidence of a relationship between platelet (PLT) count and occurrence of major hemorrhage, preterm infants are commonly transfused prophylactically when PLT counts fall below an arbitrary limit, and this threshold is usually higher than for older infants or adults. This liberal practice has been influenced by the observation that, in vitro, neonatal PLTs are hyporeactive in response to multiple agonists. However, full-term infants exhibit normal to increased primary hemostasis due to factors in neonatal blood that enhance the PLT-vessel wall interaction. Additionally, cardiorespiratory problems are considered the main etiologic factors in the development of neonatal intraventricular hemorrhage. In this review, we will discuss the developmental differences that exist in regard to PLT production and function, as well as in primary hemostasis in preterm and term neonates, and the implications of these developmental differences to transfusion medicine. PLT transfusions are not exempt of risk, and a better understanding of the PLT function and the hemostatic profile of premature infants and their changes over time and in response to illness is the starting point to design randomized controlled trials to define optimal use of PLT transfusions in premature neonates. Without these future trials, the marked disparities in PLT transfusion practice in neonates between hospitals and countries will remain over time.

Predicting risk severity and response of fetal neonatal alloimmune thrombocytopenia

Fetal neonatal alloimmune thrombocytopenia (FNAIT) is a devastating bleeding disorder in the fetus or neonate caused by transplacental transport of maternal alloantibodies to paternal-derived antigen on fetal platelets. In Caucasians, up to 80% of FNAIT cases result from maternal immunization to human platelet antigen (HPA)-1a. New methods have developed facilitating detection of common and private antibodies against HPAs triggering FNAIT. Understanding the pathogenesis of FNAIT made it possible to develop a novel strategy to treat this disorder. To date, recombinant monoclonal antibodies directed against the β3 integrin and Fc receptors have been tested in a mouse model of FNAIT, and seem to be promising. Whether those novel treatments will eventually replace the conventional high dose immunoglobulin G in women with FNAIT is yet unknown.

Neonatal alloimmune thrombocytopenia: pathogenesis, diagnosis and management

Neonatal alloimmune thrombocytopenia, (NAIT) is caused by maternal antibodies raised against alloantigens carried on fetal platelets. Although many cases are mild, NAIT is a significant cause of morbidity and mortality in newborns and is the most common cause of intracranial haemorrhage in full-term infants. In this report, we review the pathogenesis, clinical presentation, laboratory diagnosis and prenatal and post-natal management of NAIT and highlight areas of controversy that deserve the attention of clinical and laboratory investigators.

Thrombocytopenia, bleeding, and use of platelet transfusions in sick neonates

Survival rates for infants born prematurely have improved significantly, in part due to better supportive care such as RBC transfusion. The role of platelet transfusions in neonates is more controversial. Neonatal thrombocytopenia is common in premature infants. The primary causal factors are intrauterine growth restriction/maternal hypertension, in which the infant presents with thrombocytopenia soon after birth, and sepsis/necrotizing enterocolitis, which are the common morbidities associated with thrombocytopenia in neonates > 72 hours of age. There is no evidence of a relationship between platelet count and occurrence of major hemorrhage, and cardiorespiratory problems are considered the main etiological factors in the development of intraventricular and periventricular hemorrhage in the neonatal period. Platelet transfusions are used commonly as prophylaxis in premature neonates with thrombocytopenia. However, there is widespread variation in the pretransfusion thresholds for platelet count and evidence of marked disparities in platelet transfusion practice between hospitals and countries. Platelet transfusions are biological agents and as such are associated with risks. Unlike other patient groups, specifically patients with hematological malignancies, there have been no recent clinical trials undertaken comparing different thresholds for platelet transfusion in premature neonates. Therefore, there is no evidence base with which to inform safe and effective practice for prophylactic platelet transfusions. There is a need for randomized controlled trials to define the optimal use of platelet transfusions in premature neonates, who at present are transfused heavily with platelets.