儿童全血细胞减少的临床特点和病因诊断

目的：探讨儿童全血细胞减少的临床特点及常见病因,以提高临床诊断水平。方法：收集2003年9月至2010年1月收治的174例全血细胞减少初治患儿的临床资料,对其临床表现、实验室检查、诊断结果进行分析。结果：患儿就诊时主要表现为面色苍白147例（84.5%）,出血87例（50.0%）,发热41例（23.6%）。血常规主要表现为轻中度贫血、血小板重度减少、白细胞轻度减少。174例患儿中由造血系统疾病引起的全血细胞减少有155例（89.1%）,非造血系统疾病（病毒感染、系统性红斑狼疮、脾功能亢进、神经母细胞瘤）6例（3.4%）,13例（7.5%）原因不明。再生障碍性贫血为最常见的病因（91例,52.3%）,其次为骨髓增生异常综合征（37例,21.3%）、急性白血病等血液系统肿瘤（11例,6.3%）、噬血细胞综合征（6例,3.4%）。结论：儿童全血细胞减少以贫血、出血、发热为主要临床表现,病因以再生障碍性贫血最常见,骨髓增生异常综合征、急性白血病等血液系统肿瘤、噬血细胞综合征等亦为常见病因。     

母体高尿酸血症对妊娠结局和新生儿合并症影响的回顾性巢式病例对照研究

背景：高尿酸血症（HUA）患病率逐年增高,不仅与痛风、尿酸盐肾病和肾结石有关,还与内分泌代谢、心脑血管等系统疾病的发生和发展有关。 目的：探讨孕母妊娠晚期血尿酸水平与不良妊娠结局、新生儿尿酸水平及新生儿合并症的关系。 设计：回顾性巢式病例对照研究。 方法：以2020年1~12月在北京大学人民医院产检的孕母为队列人群,根据孕母妊娠晚期血尿酸水平分为HUA组和非HUA组,比较两组妊娠结局和新生儿临床结局。根据孕母妊娠晚期血尿酸水平（μmol·L-1）分为低浓度（<360）、中浓度（~420）和高浓度（>420）,采用线性回归和Logistic 回归模型分析孕母血尿酸水平与早产、低出生体重、小于胎龄儿的关系。孕母妊娠晚期尿酸值及新生儿生后24 h尿酸值相关性分析采用Spearman秩相关分析。 主要结局指标：孕母血尿酸水平与早产、低出生体重和小于胎龄儿的关系。 结果：共纳入孕母2 397例（新生儿2 581例）,HUA组216例（9.0%）,非HUA组2 181例。HUA组孕母所生新生儿出生体重低于非HUA组（2 925 g vs 3 260 g,P<0.001）,差异均有统计学意义;而早产（18.5% vs 8.9%）、低出生体重（23.1% vs 7.1%）、小于胎龄儿（29.2% vs 10.6%）和转儿科比例（19.9% vs 11.1%）均高于非HUA组,差异均有统计学意义（P<0.001）。尿酸水平高浓度组孕母分娩的新生儿出生体重较低浓度组低54.0 g（95%CI：-106.5~-1.6,P=0.043）,发生早产的风险增加74%（OR=1.74,95%CI：1.08~2.8,P=0.023）,发生小于胎龄儿的风险增加85%（OR=1.85,95%CI：1.26~2.73,P=0.002）。新生儿生后24 h内尿酸水平与孕母妊娠晚期尿酸水平呈中等相关（r=0.613,P=0.000）。两组早产儿合并症差异无统计学意义。 结论：母体妊娠晚期HUA与早产、低出生体重、小于胎龄儿的发生相关。     

妊娠合并急性胰腺炎对妊娠结局及新生儿的影响

目的 探讨妊娠合并急性胰腺炎（APIP）对妊娠结局及新生儿的影响。方法 以33例APIP患者及其31例活产新生儿为研究对象,对孕产妇及其新生儿进行回顾性分析。结果 33例APIP中发生于妊娠晚期的最多（26例,79%）。从病因分析,以高脂血症性最多（14例,45%）,胆源性13例（42%）,其他类型4例（13%）;从严重程度分析,以轻度最多（22例,67%）,中度最少（5例,15%）。33例APIP患者中病死率为0。足月分娩的20例中终止妊娠的11例,早产10例中终止妊娠的9例,2例发生胎死宫内,1例于孕中期发生流产。31例活产新生儿（其中2例为双胎）中1例（3%）死亡,12例（39%）发生新生儿高胆红素血症,8例（26%）发生新生儿低血糖症,6例（19%）发生新生儿呼吸窘迫综合征,5例（16%）发生感染性疾病,2例（6%）发生颅内出血。胆源性、高脂血症性和其他类型所致APIP 3组所娩新生儿中早产儿的比例、出生体重以及新生儿各疾病发生率的差异均无统计学意义（P > 0.05）,但终止妊娠以高脂血症性APIP组最多（P < 0.05）。轻、中、重度3组以中度组娩出的早产儿最多（P < 0.05）;所娩新生儿的出生体重以中度组最低（P < 0.05）;所娩新生儿呼吸窘迫综合征、颅内出血、感染性疾病的发生率以轻度组最低（P < 0.05）。结论 妊娠合并急性胰腺炎可导致不良妊娠结局和新生儿疾病发生,并且与胰腺炎的严重程度相关。     

儿童新诊断免疫性血小板减少症与幽门螺杆菌感染的相关性研究

目的明确幽门螺杆菌(H.pylori)感染对儿童新诊断免疫性血小板减少症(ITP)的影响。方法选取2011年1月至2013年12月间首次住院并新诊断为ITP的495例患儿为病例组;随机选取无血小板减少及其他血液系统疾病的普通呼吸道感染住院患儿123例作为对照组。依据年龄将两组患儿分为1岁组(n=219)、1岁~组(n=161)、3岁~组(n=76)和7~14岁组(n=39)。回顾性分析各年龄段患儿H.pylori感染率,以及H.pylori感染阳性及阴性ITP患儿经过相同治疗后的预后情况。结果病例组中H.pylori感染率随着ITP患儿年龄的增长而增加,与对照组各年龄段H.pylori感染率比较差异均无统计学意义(均P0.05)。H.pylori感染阳性ITP患儿均未接受针对H.pylori的相关治疗,而针对血小板减少经丙种球蛋白和/或激素治疗后缓解率随着年龄的增长而呈现逐渐下降趋势,与各年龄段H.pylori阴性的ITP患儿治疗后缓解率比较差异均无统计学意义(均P0.05)。结论 H.pylori感染可能不是ITP患儿发病的一个主要致病因素;是否治疗H.pylori并不影响儿童急性ITP的治疗效果。     

系统性红斑狼疮合并妊娠子代早产儿42例临床分析

目的 探讨系统性红斑狼疮（SLE）合并妊娠子代早产儿的临床特点,提高新生儿科医师对这部分早产儿的认识。方法 收集2000年1月至2012年6月间SLE合并妊娠子代早产儿的临床资料进行回顾性分析,并与同期出生的除SLE合并妊娠子代早产儿以外的2 308例早产儿住院期间并发症发生情况进行对比。结果 SLE合并妊娠子代早产儿共42例,女婴比例明显高于男婴,其中确诊新生儿狼疮综合征4例。新生儿感染为SLE合并妊娠子代早产儿最常见并发症（47.62%）,其次为小于胎龄儿（28.57%）,新生儿呼吸窘迫综合征（26.19%）,新生儿窒息和先天性心脏病（均为14.29%）,肺出血（4.76%）;与同期收治的2 308例早产儿合并新生儿感染（16.81%）、小于胎龄儿（13.21%）和先天性心脏病（5.16%）的发生率进行比较,差异均有统计学意义（均P<0.05）;其他合并症的发生率在两组早产儿间比较差异均无统计学意义。结论 SLE合并妊娠子代早产儿易合并感染性疾病、小于胎龄儿及先天性心脏病,而呼吸方面并发症与同期其他早产儿相比无显著差异。     

非免疫性胎儿水肿新生儿的临床特征及预后分析

目的 分析非免疫性胎儿水肿（NIHF）新生儿的临床特征、病因及转归情况。方法 回顾性分析23例NIHF新生儿的临床资料及转归。结果 23例NIHF患儿中,早产儿18例（78%）,足月儿5例（22%）;出生窒息12例（52%）,其中重度窒息6例。NIHF病因包括双胎输血综合征（TTTS）8例（35%）,心血管畸形3例（13%）,微小病毒B19感染3例（13%）,先天性乳糜胸2例（9%）,Turner综合征1例（4%）,柯萨奇病毒感染1例（4%）,病因不明5例（22%）。临床治愈13例（57%）,死亡10例,新生儿期病死率为43%。死亡组中早产儿、新生儿窒息、5分钟Apgar评分<8分及心力衰竭比例（分别为100%、100%、60%、60%）明显高于存活组（分别为62%、15%、8%、8%）（P < 0.05）。结论 NIHF新生儿易发生出生窒息;胎龄越小、窒息程度越重、合并心力衰竭者新生儿期死亡风险越大。TTTS中受血儿是NIHF的主要病因。     

母亲妊娠期患病对其早产儿的影响北大核心CSCD

目的 探讨母亲妊娠期患病对其早产儿的影响.方法 选取北京大学人民医院儿科2012年1月至12月收治的早产儿187例,根据其母亲妊娠期情况分为母亲妊娠期患病组（观察组）及母亲妊娠期未患病组（对照组）.分析2组早产儿一般情况、早产原因、早产并发症等方面有无差异,并统计早产儿母亲妊娠期患病的主要类型.结果 观察组早产儿剖宫产分娩率[71.8％（84/117例）]及宫内窘迫发生率[9.4％（11/117例）]较对照组[52.9％（37/70例）、1.4％（1/70例）]显著增高,差异均有统计学意义（x2=6.878,P＜0.01;x2=5.246,P＜0.05）;观察组适于胎龄儿比例[76.0％（89/117例）]较对照组[88.6％（62/70例）]低,差异有统计学意义（,=4.404,P＜0.05）.观察组母亲患病以慢性高血压、妊娠高血压病、妊娠期糖尿病及糖尿病合并妊娠为主要类型,分别占49.6％（58/117例）、23.0％（27/117例）、38.5％（45/117例）、14.5％（17/117例）.在早产原因方面,观察组因母亲妊娠患病引起早产的比例为51.3％（60/117例）,显著高于其他原因.观察组早产儿因胎膜早破发生早产比例较对照组低[18.80％（22/117例）比47.10％（33/70例）,x2=16.94,P＜0.01].观察组早产儿窒息[13.70％（16/117例）]、低血糖[17.10％（20/117例）]发生率较对照组早产儿[2.90％（2/70例）、4.30％（3/70例）]高,差异均有统计学意义（x2=5.892、6.661,P均＜0.05）.观察组早产儿新生儿高胆红素血症发生率较对照组低[6.80％（8/117例）比17.10％（12/70例）,x2 =4.87,P＜0.05].结论 高血压及糖尿病为早产儿母亲妊娠期患病的主要类型.母亲妊娠期患病可影响胎儿的宫内生长,增加围生期缺氧及低血糖的发生率,并使剖宫产分娩率增加.     

IVIG与IFN治疗原发性血小板减少性紫癜疗效观察

本文对1994年～1995年我院收治的42例原发性血小板减少性紫癜（ITP）回顾性疗效分析，比较单纯使用激素与应用静脉注射丙种球蛋白（IVIG）、干扰素（IFN）两组病人血小板的回升日及ITP的转归。一、临床资料和方法42例ITP诊断均符合1986年杭州会议所定的ITP诊断标准。发病最大12     

试管早产儿早期并发症及治疗转归

目的：探讨试管早产儿早期并发症的发生率及治疗转归。方法：回顾性分析并比较122例试管早产儿与183例自然妊娠早产儿（对照组）母亲围产期情况、出生一般情况及早期并发症的发生情况。结果：两组孕母围产期疾病的发生率差异无统计学意义（P>0.05）。试管早产儿新生儿呼吸窘迫综合征（RDS）发生率（25.4%）高于对照组（12.0%）,差异有统计学意义（P<0.05）;试管组先天性畸形发生率（3.3%）高于对照组（0%）,差异有统计学意义（P<0.05）;试管组病死率（9.0%）高于对照组（2.2%）,差异有统计学意义（P<0.05）。结论：试管早产儿与自然妊娠早产儿相比,更易患RDS,且畸形率及病死率均较自然受孕儿高,故仍应慎重选择辅助生殖技术的方式,并加强孕产期监护。     

早期新生儿腹胀临床分析

目的 腹胀是新生儿患者常见症状,严重时可危及生命,因此应尽快明确腹胀原因,避免严重后果。该文旨在探讨早期新生儿腹胀的临床特点,为临床医生对腹胀的病因诊断和鉴别诊断提供帮助。方法 回顾性分析2011年1月至2012年12月有腹胀主诉和临床表现的201例早期新生儿临床特点,其中早产儿65例,足月儿136例。结果 先天畸形（包括先天性巨结肠、肛门闭锁、肠旋转不良、肠闭锁、肠重复畸形、后尿道瓣膜）为早期新生儿腹胀的主要病因,分别为早产组44.6%、足月组61.8%。就单病种而言,败血症为早产组第1位及足月组第2位病因,分别为35.4%和21.3%;先天性巨结肠为足月组第1位及早产组第2位病因,分别为33.8%和13.8%。呕吐为腹胀的主要伴随症状,在足月组占64.0%,早产组占44.6%。早产组以肠胀气可见液平为第1位X线表现,占47.7%,足月组占30.1%。足月组以肠胀气为第1位X线表现,占57.3%,早产组占40%。对因及对症治疗后,早产组86.2%、足月组88.2%的患儿以治愈或好转为转归,组间差异无统计学意义。结论 先天畸形为腹胀早期新生儿主要病因;就单病因而言,败血症和先天性巨结肠分别为早期早产儿和早期足月儿的第1位病因;呕吐是早期新生儿腹胀的主要伴随症状;早期早产儿X线表现较足月儿严重;两组患儿转归均较好。     

Thrombocytopenic syndromes masquerading as childhood immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is the most common cause of thrombocytopenia in children and adolescents. However, there are a number of other diagnoses that are often mistaken for ITP. A 10-year retrospective chart review was performed at the Children's Hospital of Alabama to characterize ITP. Initially, 492 patients who had the coded diagnosis of ITP (ICD 287.3) were identified. However, 83 (17%) of patients were found to have alternative diagnoses on chart review. Of the 83 patients, 13 patients (3%) represented coding errors or study classification errors. The 70 remaining patients (14%) had an alternative explanation for their thrombocytopenia, consisting of 31 different diagnoses. The most common diagnoses were familial thrombocytopenia (10%), systemic lupus erythematosus (9%), hypersplenism (9%), neonatal alloimmune thrombocytopenia (7%), Wiskott-Aldrich syndrome (7%), or systemic infection (6%). In total, 16 of the patients (23%) were ultimately diagnosed with one of a number of congenital syndromes with concurrent thrombocytopenia. Although this review confirms that most children with thrombocytopenia are diagnosed with ITP, 14% of the study population manifested other diagnoses. The clinician evaluating a child with thrombocytopenia must keep an open mind about the possible diagnosis and perform a comprehensive and thoughtful evaluation based on the clinical picture. ITP must be a diagnosis of exclusion as misdiagnosis in a child with thrombocytopenia may have a significant impact on morbidity and mortality.     

Plasma transforming growth factor beta1 levels in thrombocytopenic and nonthrombocytopenic neonates

In this study, we determined the plasma TGF-beta1 levels in healthy and thrombocytopenic and nonthrombocytopenic neonates who had perinatal risk factors and examined the association between plasma TGF-beta1 levels and platelet counts in these newborns to investigate the role of TGF-beta1 in the pathogenesis of neonatal thrombocytopenia. Three groups were defined in this prospective study: group 1, thrombocytopenic neonates (n=22) who had perinatal risk factors; group 2, nonthrombocytopenic neonates who had similar perinatal risk factors for thrombocytopenia (n=20); group 3, healthy and nonthrombocytopenic neonates without any risk factors (n=20). Plasma TGF-beta1 levels were measured with ELISA. Plasma TGF-beta1 levels of the thrombocytopenic neonates were significantly lower than those of healthy nonthrombocytopenic neonates but did not differ significantly from nonthrombocytopenic neonates who had similar perinatal risk factors for thrombocytopenia. There was a significant positive correlation between plasma TGF-beta1 levels and platelet counts. Further studies are needed to determine the cause of low plasma TGF-beta1 levels in thrombocytopenic neonates and to investigate the role of plasma TGF-beta1 levels in the pathogenesis of neonatal thrombocytopenia.     

Clinical and diagnostic comparison of neonatal alloimmune thrombocytopenia to non-immune cases of thrombocytopenia

BACKGROUND: Affected patients with neonatal alloimmune thrombocytopenia (AIT) are often severely thrombocytopenic and, if so, may suffer an intracranial hemorrhage (ICH). This study was undertaken to compare the outcome of cases of AIT to cases of neonatal thrombocytopenia shown not to be AIT and to identify clinical features that would facilitate the diagnosis. PROCEDURE: Two hundred twenty two cases of neonatal thrombocytopenia for which serologic testing was obtained by the referring physician were accrued for this study from 11 testing laboratories. The relevant clinical information was pursued. RESULTS: The mean birth platelet count in 110 neonates with AIT was 26,000/mm(3) x 10(9)/L and the rate of ICH was 11% (not all neonates had head sonos). Three criteria distinguished cases of AIT from other causes of neonatal thrombocytopenia (n = 56): (1) severe thrombocytopenia <50,000/mm(3) x 10(9)/L; (2) ICH associated with 1 or more of: a 1-min Apgar score >5, birthweight >2,200 g, grade >1, antenatal occurrence, or signs of bleeding, that is, petechiae, ecchymoses; and (3) no additional, non-hemorrhagic neonatal medical problems. CONCLUSIONS: AIT is a unique type of neonatal thrombocytopenia with significant hemorrhagic consequences. Identification of AIT at the bedside should guide institution of appropriate treatment and lead to serologic testing for confirmation.     

Incidence of thrombocytopenia in infants born to mothers with idiopathic thrombocytopenic purpura

Abstract Neonatal thrombocytopenia related to maternal idiopathic thrombocytopenic purpura (ITP) is reportedly uncommon but may have severe complications. The present report reviews records of 15 infants born to mothers with ITP during a 10-year period, and the incidence of neonatal thrombocytopenia and the risk of hematological complications is examined. Severe thrombocytopenia (platelets < 50 000/μL) was seen in three infants despite successful therapy with high-dose gamma globulin prior to delivery, which elevated maternal platelet counts. Although the platelet counts of these three infants fell to < 10 000/μL, none had severe complications. Moreover, no infants required treatment such as adrenocorticosteroids, platelets transfusion, or high doses of gamma globulin. No maternal markers predicted the degree of neonatal thrombocytopenia. The risk of complications arising from neonatal thrombocytopenia is low, but careful observation is required for the thrombocytopenic newborn of ITP mothers even when the infant has no bleeding complications at delivery.     

糖皮质激素受体表达与特发性血小板减少性紫癜激素抵抗关系

目的:通过研究原发性糖皮质激素抵抗型特发性血小板减少性紫癜（ITP）患儿糖皮质激素受体（GR）亚型GRα和GRβ表达水平,以揭示ITP糖皮质激素抵抗的可能机制。方法:应用实时荧光定量-PCR法检测18 例糖皮质激素敏感型、12例糖皮质激素抵抗型ITP患儿及10例正常儿童外周血单个核细胞GRα和GRβ mRNA 的表达水平,同时采用酶免疫分析法测定血清总皮质醇水平。结果:①对照组、糖皮质激素敏感组和抵抗组3组之间GRα mRNA的表达水平差异无显著性;对照组和糖皮质激素敏感组的GRβ mRNA水平差异无显著性,但糖皮质激素抵抗组的GRβ mRNA水平显著高于对照组和糖皮质激素敏感组,差异有显著性（P<0.01）。②总皮质醇水平在对照组与糖皮质激素敏感组之间差异无显著性,但糖皮质激素抵抗组总皮质醇水平明显高于糖皮质激素敏感组,差异有显著性（P<0.01）。结论: ITP患儿糖皮质激素抵抗可能与GRβ mRNA的表达增高有关。［中国当代儿科杂志,2009,11（9）：714-716］     

Neonatal thrombocyte values in children with Down's syndrome and other autosome trisomies]

Platelet counts were determined in 70 neonates with trisomy-21, 10 neonates with trisomy-18 and 6 neonates with trisomy-13 during the first days of life. 60% of all infants with trisomy-aberrations were found to have thrombocytopenia. Platelet counts in Down's syndrome averaged 104600 (SD 53000; median 90500; 10- and 90-percentile at 45000 and 175000) per microliter. A correlation with other hematological features of trisomy-21 was examined. There was no significant correlation between platelet counts and hemoglobin concentration. Similarly the difference in platelet counts between trisomy-neonates with and without polycythemia was statistically not significant. In contrast, 27 normal neonates with polycythemia showed significantly higher platelet counts (mean = 13400) than their trisomy-counterparts (mean = 98900; P = 0.01). In addition, there was no correlation, in trisomy infants, between either erythroblastosis or low birth weight and platelet count. These findings point to defective hematopoiesis as a primary cause of thrombocytopenia in trisomy-infants.     

辅助生殖技术双胎妊娠对新生儿结局的影响

目的 比较辅助生殖技术（ART）双胎妊娠与自然受孕（SC）双胎妊娠对新生儿结局的影响。方法 回顾性纳入南京市妇幼保健院2017~2019年期间分娩的胎龄≥ 24周活产双胎儿3 356例,其中ART组双胎儿2 006例（1 003对）,SC组双胎儿1 350例（675对）,收集母亲一般资料、妊娠期合并症及新生儿一般资料、新生儿疾病及结局,进行两组间比较。结果 ART组母亲平均年龄大于SC组（P < 0.05）,初产率、剖宫产率及宫颈环扎手术率高于SC组（P < 0.05）。ART组母亲妊娠相关合并症,如高血压、糖尿病及产后出血发生率均高于SC组（P < 0.05）。ART组新生儿平均胎龄低于SC组（P < 0.05）,极低出生体重儿比例高于SC组（6.8% vs 5.8%,P < 0.05）,但ART未增加早产及低Apgar评分的风险。两组新生儿的病死率及新生儿疾病,如呼吸窘迫综合征、Ⅱ/Ⅲ期坏死性小肠结肠炎、支气管肺发育不良、Ⅲ~Ⅳ级颅内出血的发生率差异均无统计学意义（P > 0.05）。结论 与SC双胎妊娠相比,ART双胎妊娠未明显增加新生儿病死率及不良结局。     

儿童原发免疫性血小板减少症miR-106b-5p的表达及其与T细胞的相关性研究北大核心CSCD

目的 探讨血浆miR-106b-5p在原发免疫性血小板减少症(primary immune thrombocytopenia,ITP)中的表达及其与辅助性T细胞17(T helper cells 17,Th17)、调节性T细胞(T regulatory cell,Treg)、Th17/Treg的相关性。方法 选取79例ITP患儿(ITP组)和40例健康儿童(对照组)为研究对象。79例ITP患儿根据治疗效果分为完全有效组(40例)、有效组(18例)、无效组(21例)。采用实时荧光定量PCR技术检测miR-106b-5p表达水平,流式细胞技术检测Th17和Treg,计算Th17/Treg,分析血浆miR-106b-5p表达水平与Th17、Treg及Th17/Treg的相关性。结果 ITP组miR-106b-5p、Th17及Th17/Treg水平高于对照组(P<0.05),Treg水平低于对照组(P<0.05)。ITP组患儿治疗后miR-106b-5p、Th17、Th17/Treg水平低于治疗前(P<0.05),Treg水平高于治疗前(P<0.05)。完全有效组miR-106b-5p、Th17、Th17/Treg水平低于有效组和无效组(P<0.05),Treg水平高于有效组和无效组(P<0.05)。相关分析显示,ITP患儿血浆miR-106b-5p表达水平与Th17、Th17/Treg均呈正相关(分别r=0.730、0.816,均P<0.001),与Treg呈负相关(r=-0.774,P<0.001)。结论 ITP患儿存在miR-106b-5p高表达和Th17/Treg比例失衡,在ITP患儿治疗过程中检测miR-106b-5p、Th17、Treg及Th17/Treg水平,对ITP患儿的疗效判断具有较好的指导作用。     

Neonatale Thrombozytopenie

Thrombocytopenia is the most common hematological abnormality in the investigation of the blood picture of preterm and term neonates. For the initial evaluation of thrombocytopenia five criteria are very useful. (1) Onset within 72?h after birth (early onset vs. late onset beginning >72h after birth), (2) clinically ill vs. otherwise healthy neonate, (3) the severity (<50??×?10⁹/l) and kinetics of thrombocytopenia (reduction in platelet numbers of >50??×?10⁹/l per day), (4) the likelihood of a maternal/placental or a fetal/neonatal cause and (5) dysmorphic stigmata or malformations as indications for a systemic disorder. If thrombocytopenia persists longer than 10 days specific diagnostics are recommended, including the analysis of platelet morphology, measurement of the immature platelet fraction (IPV) and/or of the mean platelet volume (MPV) and the measurement of transaminases. The individual risk of bleeding depends not only on the cause of thrombocytopenia but also on the specific biology of fetal/neonatal platelets as well as on the plasmatic coagulation system and the vascular endothelium. As controlled trials have not provided any evidence that prophylactic platelet transfusion reduces the risk of bleeding in neonates without primary hematological or immunological causes of thrombocytopenia, restrictive platelet transfusion thresholds have become established in non-bleeding neonates.