Vox Sanguinis (2014) 106, 361–367 ORIGINAL PAPER © 2013 International Society of Blood Transfusion DOI: 10.1111/vox.12105 Early-onset thrombocytopenia in near-term and term infants with perinatal asphyxia N. Boutaybi, 1 S. J. Steggerda, 1 V. E. H. J. Smits-Wintjens, 1 E. W. van Zwet, 2 F. J. Walther 1 & E. Lopriore 1 1 Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands 2 Department of Medical Statistics, Leiden University Medical Center, Leiden, the Netherlands Received: 10 July 2013, revised 25 September 2013, accepted 25 September 2013, published online 29 October 2013 Background Neonates after perinatal asphyxia are at increased risk of thrombo- cytopenia. The correlation between perinatal asphyxia and the risk and severity of early-onset thrombocytopenia is not well known. Objective To estimate the incidence, severity and risk factors for early-onset thrombocytopenia in neonates after perinatal asphyxia. Methods We included all newborns (gestational age ≥ 36 weeks) admitted to our neonatal nursery due to perinatal asphyxia in this retrospective study. We col- lected platelet counts that were obtained within the first 48 h of life to estimate the incidence and severity of early-onset thrombocytopenia. Results A total number of 171 neonates with perinatal asphyxia were included in the study. The incidence of early-onset thrombocytopenia (platelet count < 150 9 10 9 /l) was 51% (87/171). Several factors were associated with increased risk of early-onset thrombocytopenia, including prolonged prothrombin time (PT) [odds ratio (OR) 1Á18, 95% confidence interval (CI) 1Á08–1Á30, P < 0Á01], prolonged activated partial thromboplastin time (APTT) (OR 1Á07, 95% CI 1Á03–1Á11, P < 0Á01), low Apgar score at 10 min (OR 1Á25, 95% CI 1Á08–1Á45, P < 0Á01) and high serum lactate (OR 1Á12, 95% CI 1Á06–1Á19, P < 0Á01). After multiple logistic regression analysis, we found an independent association between early-onset thrombocytopenia and prolonged PT (OR 1Á15, 95% CI 1Á00– 1Á33, P = 0Á045) and higher lactate level (OR 1Á15, 95% CI 1Á03–1Á28, P = 0Á01). Conclusions Early-onset thrombocytopenia occurs frequently in neonates after perinatal asphyxia and is independently associated with PT and lactate level. Key words: blood collection, blood components, platelet transfusion. Introduction Thrombocytopenia, defined as a platelet count < 150 9 10 9 /l, is a frequent problem in newborns occur- ring in 1–5% of healthy term neonates [1, 2]. The preva- lence of thrombocytopenia is higher in sick neonates (range 22–35%) admitted to neonatal intensive care units [1–4] and is associated with an increased risk of pulmo- nary, gastrointestinal and intraventricular haemorrhage (IVH) [5]. Neonatal thrombocytopenia can be caused by several disorders and is often classified depending on the time of onset [4]. Late-onset thrombocytopenia is often caused by sepsis and necrotizing enterocolitis, whereas the most common cause of early-onset thrombocytopenia is intra- uterine growth restriction, maternal disorders (pre- eclampsia, HELLP) or perinatal asphyxia [1]. The exact mechanism of thrombocytopenia in perinatal asphyxia is not clear [4]. In addition, not much is known on the correlation between the severity of perinatal asphyxia and the risk and severity of thrombocytopenia at birth [6, 7]. The aim of this study was to investigate the incidence, severity and risk factors for early-onset thrombocytopenia in near-term and term neonates with perinatal asphyxia. Correspondence: Enrico Lopriore, Department of Pediatrics, Leiden University Medical Center, J6-S, Albinusdreef 2, 2333 ZA Leiden, the Netherlands E-mail: e.lopriore@lumc.nl 361