Risk of thrombocytopenia in neonates of thrombocytopenic mothers.

OBJECTIVE: Maternal thrombocytopenia during pregnancy may occur due to several possible etiologies, with potential neonatal impact. The aim of the present study was to investigate whether there is a correlation between maternal and neonatal platelet count among women with thrombocytopenia during pregnancy. METHODS: A cross-sectional retrospective study (2012-2019) was conducted at a tertiary medical center. Complete blood count was routinely measured in all patients on admission to the delivery ward. Thrombocytopenia was defined as a platelet count below 150 K/µL. Clinical and outcome parameters of thrombocytopenic mothers and their newborns were collected from the electronic files and analyzed by severity of maternal thrombocytopenia. RESULTS: Of 45 385 women with a documented platelet count at admission, 2841 (6.24%) had thrombocytopenia: 2623 (5.7%) mild (100-149 K/µL), 207 (0.45%) moderate (50-99 K/µL), and 11 (0.02%) severe (<50 K/µL). Eight newborns had thrombocytopenia; corresponding rates by severity of maternal thrombocytopenia were 0.11%, 1.43%, and 18.18% (P = 0.04). None of the thrombocytopenic neonates had an intraventricular hemorrhage or other bleeding complications. The correlation between maternal and neonatal platelet counts was weak (Pearson r = 0.038; P = 0.046). CONCLUSION: We suggest that although the chances of neonatal thrombocytopenia are higher with worsening maternal thrombocytopenia, actual occurrence is rare, and the correlation is poor. Therefore, maternal thrombocytopenia cannot be regarded as a significant risk factor for neonatal thrombocytopenia. Neonatal platelet count should be obtained when maternal thrombocytopenia is autoimmune or less than 100 K/µL.

Early onset neonatal thrombocytopenia is associated with severe intraventricular hemorrhage in very preterm infants: A retrospective cohort study.

BACKGROUND: The role of platelet function in the development of intraventricular hemorrhage is still a subject of debate. In this study, we aimed to determine whether there is an association between platelet indices in the first week of life and severity of intraventricular hemorrhage in very preterm infants. MATERIALS AND METHODS: Preterm infants born < 30 weeks of gestation in our hospital were retrospectively evaluated. Platelet parameters, including platelet counts, mean platelet volume, platelet distribution width, and platelet mass were retrieved at two different time points: the initial value on the first day of life and the value closest to the end of the first week of life. The infants were categorized according to the findings of cranial ultrasonography as; no intraventricular hemorrhage, mild or severe intraventricular hemorrhage. RESULTS: Totally, 1051 infants were evaluated. The mean gestational age and birth weight for the entire cohort were 27.9±1.6 weeks and 1058±247 g, respectively. Infants in the severe intraventricular hemorrhage group had significantly lower gestational age (p < 0.001) and birthweight (p < 0.001) compared to other two groups. Furthermore, there were significant differences in platelet count and platelet mass between the groups at two time intervals. However, logistic regression analysis revealed that only platelet count of < 100×109/L on the first postnatal day was independently associated with the severity of intraventricular hemorrhage. CONCLUSION: There is an association between platelet count of < 100×109/L on the first postnatal day and severe intraventricular hemorrhage in very preterm infants.

Effect of delivery mode on postnatal platelet count dynamics in neonates born to mothers with immune thrombocytopenia.

We aimed to determine the effect of delivery mode on postnatal platelet count dynamics in neonates born to mothers with immune thrombocytopenia (ITP). This single-center, retrospective study included 41 mothers with ITP and their 65 infants born by vaginal delivery (VD, n = 30) and cesarean section (CS, n = 35) between January 1997 and March 2022. The median difference in platelet counts from day 0 to day 2 (ΔPlt [D 0-2]) was significantly lower in the VD group (- 39 × 109/L, interquartile range [IQR]: - 47 to - 24 × 109/L) than the CS group (15 × 109/L, IQR: - 6.5 to 33 × 109/L) (p < 0.001). The median ΔPlt (D 0-5) was significantly lower in the VD group (- 55 × 109/L, IQR: - 85 to - 31 × 109/L) than the CS group (33 × 109/L, IQR: 1-69 × 109/L) (p < 0.001). Multivariate analysis also showed a significant association of delivery mode with ΔPlt (D 0-2) and ΔPlt (D 0-5) (both p < 0.001). VD neonates with platelet counts ≥ 100 × 109/L at birth were significantly more likely than CS neonates to develop thrombocytopenia < 100 × 109/L at nadir (1/26 vs. 6/25) (p = 0.0496). Our findings indicate that mode of delivery is a useful predictor of postnatal platelet count dynamics in neonates born to mothers with ITP.

A case of neonatal thrombocytopenia due to maternal Helicobacter pylori-associated immune thrombocytopenia.

Many studies in adults have suggested an association between Helicobacter pylori (H. pylori) infection and chronic immune thrombocytopenia (ITP). In adults with ITP and H. pylori infection, eradicating H. pylori is recommended as the first-line therapy. However, the association between ITP and H. pylori in children remains controversial. Diagnosing thrombocytopenia in pregnant women is challenging but crucial because maternal ITP causes neonatal ITP through transplacental transfer of immunoglobulin G, also known as passive ITP. Herein, we report a case of neonatal passive ITP due to maternal H. pylori-associated ITP. A boy was born at term with neonatal thrombocytopenia to a mother tentatively diagnosed with gestational thrombocytopenia. However, further examination suggested that maternal thrombocytopenia was associated with H. pylori, and neonatal thrombocytopenia was diagnosed as ITP due to maternal ITP. The newborn received intravenous immunoglobulin treatment, and the thrombocytopenia did not recur. The mother was examined using esophagogastroduodenoscopy, and her rapid urease test using gastric mucosa tissue samples was positive. Subsequently, she was diagnosed with H. pylori infection and received H. pylori eradication therapy, after which her platelet count remained normal. To our knowledge, this is the first reported case of neonatal passive ITP secondary to maternal H. pylori-associated ITP. This case suggests that maternal H. pylori infection can lead to the production of platelet autoantibodies, which can destroy antibody-sensitized platelets in the mother and neonate. To summarize, H. pylori infection can also cause ITP in children. Therefore, pregnant women diagnosed with H. pylori-associated ITP should receive H. pylori eradication therapy to prevent their neonates from developing passive ITP.

Thrombocytopenia-Absent Radius Syndrome: Descriptions of Three New Cases and a Novel Splicing Variant in RBM8A That Expands the Spectrum of Null Alleles.

Thrombocytopenia-absent radius (TAR) syndrome is a rare congenital disorder characterized by the bilateral absence of the radius and thrombocytopenia, and sometimes by other skeletal, gastrointestinal, cardiac, and renal abnormalities. The underlying genetic defect is usually the compound inheritance of a microdeletion in 1q21.1 (null allele) and a low-frequency, non-coding single nucleotide variant (SNV) in the RBM8A gene (hypomorphic allele). We report three new cases from two unrelated families. The two siblings presented the common genotype, namely the compound heterozygosity for a 1q21.1 microdeletion and the hypomorphic SNV c.-21G>A in RBM8A, whereas the third, unrelated patient presented a rare genotype comprised by two RBM8A variants: c.-21G>A (hypomorphic allele) and a novel pathogenic variant, c.343-2A>G (null allele). Of the eight documented RBM8A variants identified in TAR syndrome patients, four have hypomorphic expression and four behave as null alleles. The present report expands the RBM8A null allele spectrum and corroborates the particularities of RBM8A involvement in TAR syndrome pathogenesis.

Bleeding Complications Associated with Pregnancy with Primary Immune Thrombocytopenia: A Meta-Analysis.

Introduction Immune thrombocytopenia (ITP) during pregnancy has received little attention from researchers. Reliable information about the outcome of mothers and newborns is required to properly counsel women who are pregnant or planning to become pregnant. Our primary outcomes were the frequency and severity of maternal and neonatal bleeding events in the setting of ITP in pregnancy. Mode of delivery, neonatal thrombocytopenia, and maternal/infant mortality were secondary outcomes. Material and Methods We comprehensively reviewed the prospective studies that enrolled ≥20 pregnant women with primary ITP. Two reviewers, blinded to each other, searched Medline and Embase up to February 2021. Meta-analyses of the maternal and newborn outcomes were performed. Weighted proportions were estimated by a random-effects model. Results From an initial screening of 163 articles, 15 were included, encompassing 1,043 pregnancies. The weighted event rate for bleeding during pregnancy was 0.181 (95% confidence interval [CI], 0.048-0.494). Most of these were nonsevere cases. The weighted event rates were 0.053 (95% CI, 0.020-0.134) for severe postpartum hemorrhage, 0.014 (95% CI, 0.008-0.025) for intracerebral hemorrhage, and 0.122 (0.095-0.157) for severe thrombocytopenia events in neonates (platelet count <50,000/µL). There were no reliable predictors of severe neonatal thrombocytopenia. The incidence of neonatal mortality was 1.06%. There were no maternal deaths. Conclusion Primary ITP in pregnant women is rarely associated with poor outcomes.

Platelet transfusions in a murine model of neonatal polymicrobial sepsis: Divergent effects on inflammation and mortality.

BACKGROUND: Platelet transfusions (PTxs) are often given to septic preterm neonates at high platelet count thresholds in an attempt to reduce bleeding risk. However, the largest randomized controlled trial (RCT) of neonatal transfusion thresholds found higher mortality and/or major bleeding in infants transfused at higher thresholds. Using a murine model, we investigated the effects of adult PTx on neonatal sepsis-induced mortality, systemic inflammation, and platelet consumption. STUDY DESIGN AND METHODS: Polymicrobial sepsis was induced via intraperitoneal injection of cecal slurry preparations (CS1, 2, 3) into P10 pups. Two hours after infection, pups were transfused with washed adult Green Flourescent Protein (GFP+) platelets or control. Weights, platelet counts, and GFP% were measured before 4 and 24 h post-infection. At 24 h, blood was collected for quantification of plasma cytokines. RESULTS: The CS batches varied in 24 h mortality (11%, 73%, and 30% in CS1, 2, and 3, respectively), due to differences in bacterial composition. PTx had differential effects on sepsis-induced mortality and systemic inflammatory cytokines, increasing both in mice infected with CS1 (low mortality) and decreasing both in mice infected with CS2 and 3. In a mathematical model of platelet kinetics, the consumption of transfused adult platelets was higher than that of endogenous neonatal platelets, regardless of CS batch. DISCUSSION: Our findings support the hypothesis that transfused adult platelets are consumed faster than endogenous neonatal platelets in sepsis and demonstrate that PTx can enhance or attenuate neonatal inflammation and mortality in a model of murine polymicrobial sepsis, depending on the composition of the inoculum and/or the severity of sepsis.

Risk factors for severe neonatal thrombocytopenia in cases of maternal immune thrombocytopenia.

AIM: Maternal immune thrombocytopenia (ITP) may induce neonatal thrombocytopenia (nTP), which carries a risk of neonatal haemorrhagic complications. Some risk factors for nTP have reached consensus such as maternal splenectomy and previous severe nTP, while others such as maternal platelet count have not. METHODS: We conducted a retrospective cohort study in a university hospital, including 145 neonates of mothers with ITP. We assessed the risk of severe nTP and bleeding complications. RESULTS: Severe nTP in the first 24 h after birth was more common in case of maternal splenectomy (OR = 4.4) and a previous severe nTP (OR = 46.9). Severe nTP at nadir (lowest platelet count during the initial postnatal days) was more frequent in cases of a previous neonate with severe nTP (OR = 42), maternal treatment during pregnancy (OR = 2.4) and a low maternal platelet count during pregnancy or at delivery. These risk factors were not significantly associated with an increased risk of neonatal haemorrhagic complications. CONCLUSION: In our population, we confirm the risk of severe nTP in case of maternal splenectomy or previous nTP. By monitoring the platelet count to its nadir, we identified three additional risk factors: maternal treatment during pregnancy and low maternal platelet count during pregnancy or low maternal platelet count at delivery.

Trombocitopenia neonatal: Revisión. I. Definiciones, diagnóstico diferencial, causas, trombocitopenias inmunes / Neonatal thrombocytopenia: A review. I. Definitions, differential diagnosis, causes, immune thrombocytopenia

La trombocitopenia, definida como recuento plaquetario inferior a 100 x 109/l, es un hallazgo muy frecuente en el período neonatal, que ocurre, en especial, en niños críticamente enfermos y en prematuros. Sus causas son múltiples: puede deberse tanto a enfermedades del niño como a otros factores involucrados en la interrelación niño-placenta-madre. En este primer artículo, se enumeran las causas de trombocitopenia; se plantea el enfoque diagnóstico frente a un neonato trombocitopénico y se describen detalladamente las distintas entidades correspondientes a trombocitopenias de etiología inmune. Se presentan los diferentes mecanismos causales y se revisan las distintas características de la trombocitopenia secundaria a trombocitopenia inmune materna y de la trombocitopenia neonatal aloinmune. Se describen las diversas estrategias terapéuticas disponibles para cada una de ellas, tanto para su manejo posnatal como para el prenatal. Se enfatiza sobre la gravedad de la enfermedad y las serias complicaciones y secuelas asociadas a la trombocitopenia neonatal aloinmune

Thrombocytopenia, defined as a platelet count below 100 x 109/L, is a very common finding in the neonatal period, especially in critically ill infants and preterm newborns. Its causes are multiple: it may be due both to pediatric conditions and to other factors involved in the fetal-placental-maternal interface. This initial article describes the causes of thrombocytopenia, proposes a diagnostic approach to manage a thrombocytopenic newborn infant, and provides a detailed description of the different conditions corresponding to thrombocytopenia of immune etiology. It also describes the different causative mechanisms and reviews the varying characteristics of thrombocytopenia secondary to maternal immune thrombocytopenia and neonatal alloimmune thrombocytopenia. The different treatment approaches to each of the different conditions are described both for their pre- as well as their postnatal management. The severity of thrombocytopenia and the serious complications and sequelae associated with the neonatal alloimmune thrombocytopenia are highlighted.

Neonatal thrombocytopenia: A review. I. Definitions, differential diagnosis, causes, immune thrombocytopenia. / Trombocitopenia neonatal: Revisión. I. Definiciones, diagnóstico diferencial, causas, trombocitopenias inmunes.

Thrombocytopenia, defined as a platelet count below 100 x 109/L, is a very common finding in the neonatal period, especially in critically ill infants and preterm newborns. Its causes are multiple: it may be due both to pediatric conditions and to other factors involved in the fetal-placental-maternal interface. This initial article describes the causes of thrombocytopenia, proposes a diagnostic approach to manage a thrombocytopenic newborn infant, and provides a detailed description of the different conditions corresponding to thrombocytopenia of immune etiology. It also describes the different causative mechanisms and reviews the varying characteristics of thrombocytopenia secondary to maternal immune thrombocytopenia and neonatal alloimmune thrombocytopenia. The different treatment approaches to each of the different conditions are described both for their pre- as well as their postnatal management. The severity of thrombocytopenia and the serious complications and sequelae associated with the neonatal alloimmune thrombocytopenia are highlighted.

La trombocitopenia, definida como recuento plaquetario inferior a 100 x 109/l, es un hallazgo muy frecuente en el período neonatal, que ocurre, en especial, en niños críticamente enfermos y en prematuros. Sus causas son múltiples: puede deberse tanto a enfermedades del niño como a otros factores involucrados en la interrelación niño-placenta-madre. En este primer artículo, se enumeran las causas de trombocitopenia; se plantea el enfoque diagnóstico frente a un neonato trombocitopénico y se describen detalladamente las distintas entidades correspondientes a trombocitopenias de etiología inmune. Se presentan los diferentes mecanismos causales y se revisan las distintas características de la trombocitopenia secundaria a trombocitopenia inmune materna y de la trombocitopenia neonatal aloinmune. Se describen las diversas estrategias terapéuticas disponibles para cada una de ellas, tanto para su manejo posnatal como para el prenatal. Se enfatiza sobre la gravedad de la enfermedad y las serias complicaciones y secuelas asociadas a la trombocitopenia neonatal aloinmune.

Benefits of lower neonatal platelet transfusion thresholds.

Degree of thrombocytopenia is not a predictor of bleeding risk in neonates, yet most platelet transfusions are given prophylactically in non-bleeding premature infants. Recent data support a lower platelet transfusion threshold of 25 × 109 /L in non-bleeding premature neonates and indicate that higher transfusion thresholds may be associated with harm including increased risk of death and bleeding. The mechanism of increased adverse events with higher platelet transfusion threshold is unknown, but considerations include adult platelets disrupting the neonatal hemostatic balance of hypoactive platelets in a hypercoagulable and fragile environment and having a pro-inflammatory effect.

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.

The influences of mothers with moderate and severe gestational thrombocytopenia and primary immune thrombocytopenia on neonates / 中国新生儿科杂志

Objective:To study the effects of maternal moderate and severe gestational thrombocytopenia (GT) and primary immune thrombocytopenia (ITP) on neonates.Method:From Jan 2018 to Dec 2019, pregnant women with platelet count <100×10 9/L during pregnancy admitted to our hospital were retrospectively reviewed. The infants were assigned into GT group and ITP group according to their mothers' diagnoses. The clinical outcomes were compared between the two groups. Result:Of 104 mothers with platelet count <100×10 9/L, 32 (30.8%) were diagnosed with ITP and 72 (69.2%) with GT. Gestational age (GA) of the ITP group was smaller than the GT group [(37.0±1.5) weeks vs. (38.0±2.0) weeks, P<0.05]. The maternal platelet count within 24 h before delivery (39×10 9/L vs. 86×10 9/L) and the lowest platelet count during pregnancy (17×10 9/L vs. 75×10 9/L) in the ITP group were both lower than the GT group, the differences were statistically significant ( P<0.001). The maternal platelet count after birth in ITP group were lower than the GT group (184×10 9/L vs. 277×10 9/L, P<0.01). Neonates in the ITP group have an increased tendency to develop neonatal thrombocytopenia (NT) than the GT group (43.8% vs. 6.9%, P<0.001). The platelet count on the first day after birth (92×10 9/L vs. 170×10 9/L) and the lowest platelet count (43×10 9/L vs. 103×10 9/L) of NT newborns in the ITP group were lower than the GT group ( P<0.05). No differences existed for the time needed reaching the lowest platelet count in NT newborns between the two groups [(3.5±1.2) d vs. (4.4±0.4) d, P>0.05]. Neither group had intracranial hemorrhage. Conclusion:Neonates born to pregnant mother with platelet count <100×10 9/L have a tendency to develop NT. The incidence of NT in neonates born to mothers with ITP is higher than GT, but the overall prognosis of the newborns is good.

Management of immune thrombocytopenia in women: current standards and special considerations.

Introduction: Immune thrombocytopenia (ITP) is an acquired autoimmune disorder, with an incidence rate of 20-40/million adults/year and an estimated prevalence in women of childbearing age of 24.5/million.Areas covered: Authors discuss management of ITP in pregnancy, treatment-related toxicity, delivery, neonatal thrombocytopenia and breastfeeding, and other women's specific issues. The search of papers published between January 1990 and December 2019 was done on PubMed using combinations of the keywords below. The distinction between ITP and other thrombocytopenias in pregnancy is of paramount importance. The current belief (at variance with the past) that ITP is a relatively benign disease pregnancy is emphasized.Expert opinion: The lack of randomized, prospective, controlled studies hampers evidence-based statements. Remarkably, ITP diagnosis is still one of exclusion, there are no clinical or laboratory criteria for prognosis and we still need more solid data on the risks related to neonatal thrombocytopenia. Corticosteroids and IVIG remain the mainstay of treatment, since rituximab, thrombopoietin-receptor agonists, fostamatinib may be toxic in pregnancy. Safety and efficacy of recombinant-human-thrombopoietin, available in China, require confirmation studies. Quality of life and women-related toxicity of treatments in young girls, adults, and elders are still an orphan area of investigation.

[Diagnosis and management of severe neonatal thrombocytopenia due to maternal alloimmunization against fetal platelet antigens: case study and literature review]. / Diagnostic et prise en charge d´une thrombopénie néonatale sévère par allo-immunisation materno-fœtale: rapport d´un cas et revue de la littérature.

Thrombocytopenia is a common hematologic disorder in the neonatal period. It can occur in neonates hospitalized in the Intensive Care Unit and in preterm infants. It is characterized by a platelet count of less than 150.000/mm3. In the context of immune thrombocytopenia, neonatal thrombocytopenia due to maternal alloimmunization (estimated at 1 per 1000 live births) is not a rare event but it is often undiagnosed in minor forms. This is caused by maternal immunization against fetal platelet antigens inherited from the father and lacking in the mother. Maternal IgG alloantibodies cross the placenta causing fetal platelet destruction. In severe thrombocytopenia, consequences can be severe, with intracranial bleeding occurring in 10-30% of patients. Diagnosis is essentially based on clinical examination and must be suspected by pediatricians.

Pregnancy of patients with idiopathic thrombocytopenic purpura: maternal and neonatal outcomes

Objective: Thrombocytopenia occurs in 7% of pregnant women. Along with other causes, idiopathic thrombocytopenic purpura (ITP), which is an autoimmune disease with autoantibodies causing platelet destruction, must be considered in the differential diagnosis. Antiplatelet antibodies can cross the placenta and cause thrombocytopenia in the newborn. The aim of our study was to assess the management of ITP in pregnancy, and to investigate neonatal outcomes. Material and Methods: This retrospective study was conducted in a tertiary center including 89 pregnant patients with ITP followed between October 2011 and January 2018. Patients were evaluated in two groups according to diagnoses of ITP and chronic ITP. Age, obstetric history, ITP diagnosis, and follow-up period, presence of splenectomy, platelet count during pregnancy and after birth, treatment during pregnancy, route of delivery, weight and platelet count of newborn, sign of hemorrhage, and fetal congenital anomaly were assessed. Results: Considering the ITP and chronic ITP groups, no significant difference was seen with respect to parity, timing of delivery, preoperative and postoperative platelet counts, and hemoglobin values. Route of delivery, birth weight, APGAR scores, newborn platelet count, and congenital anomaly rates were also similar. The timing of treatment was different because patients whose diagnoses were established during pregnancy were mostly treated for preparation of delivery. Treatment modalities were similar. Conclusion: Probability of severe thrombocytopenia at delivery is higher in patients with ITP who are diagnosed during pregnancy when compared with patients who received prepregnancy diagnoses. ITP is an important disease for both the mother and newborn. Patients should be followed closely in cooperation with the hematology department.

Risk factors associated with neonatal thrombocytopenia in pregnant women with immune thrombocytopenic purpura.

Objectives: To characterize the risk factors associated with neonatal thrombocytopenia among pregnant women with immune thrombocytopenic purpura (ITP).Methods: We reviewed the records of ITP patients who delivered during 2006-2016 at our medical center.Results: Of 253 pregnancies, median maternal age at diagnosis was 29 [25-33] years, 222 (87.7%) had previously-diagnosed ITP and 31 (12.3%) were diagnosed with new-onset ITP during pregnancy. Baseline characteristics were comparable between the groups except for a higher proportion of nulliparity among those with new-onset disease (p = .002). Maternal nadir platelet count was significantly lower among those with new-onset compared to previously diagnosed ITP (median 62 × 109/L versus 81 × 109/L, p = .005). Neonatal thrombocytopenia (<150 × 109/L) was encountered in 24 (9.5%) pregnancies and required treatment in 12 (50%) of them. Neonatal platelet count was directly correlated with maternal platelet count at delivery (r = 0.23, p = .01), with significantly lower maternal platelet count among those whose newborns experienced thrombocytopenia (p < .001). Neonatal thrombocytopenia followed a higher proportion of pregnancies of women with new-onset than previously diagnosed ITP (22.6 versus 7.7%, p = .02). In multivariate analysis, the presence of new-onset ITP (odds ratio [95% CI]: 4.88 (1.68, 14.16), p = .004) was the only independent predictor of the development of neonatal thrombocytopenia.Conclusion: Neonatal thrombocytopenia presented following almost one-tenth of pregnancies with ITP. New pregnancy-onset disease was the only prognostic marker for neonatal thrombocytopenia. This finding could contribute to risk stratification and individualized patient management.

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.

Foetal and neonatal alloimmune thrombocytopenia.

Foetal or neonatal thrombocytopenia results from alloimmunisation during pregnancy. Maternal alloantibodies can be formed following exposure to paternally derived human platelet antigens (HPAs) on foetal platelets, in case of incompatible HPA type. These alloantibodies are of the immunoglobulin G subclass and can therefore enter the foetal circulation through active placental transport mediated by the neonatal Fc-receptor. After entering the foetal circulation, these alloantibodies can cause destruction of foetal platelets and potentially damage other foetal cells containing the specific antigen. Subsequent clinical presentation in foetuses or neonates can vary widely, from an asymptomatic thrombocytopenia to a broad spectrum of bleeding complications. Most frequently encountered are minor skin haemorrhages, such as hematomas or petechiae, but also more devastating haemorrhages can occur. Of these, an intracranial haemorrhage is the most feared complication because of its high risk of life-long major neurological handicaps or perinatal death.