Study of risk factors for neonatal thrombocytopenia in preterm infants


Background: Thrombocytopenia is a common hematological problem in neonatal care units. Neonatal thrombocytopenia has been defined as platelet count less than 150x109 /L, regardless of gestational age.Objectives: To determine the frequency and assess the severity of neonatal thrombocytopenia in preterms, and the maternal and neonatal conditions as risk factors. Patients and methods: A cross sectional study was carried out in the neonatal care unit of Child Central Teaching Hospital/ Baghdad, over a period of six months (30th of June to 31st of December 2013). Study group included only preterms who had thrombocytopenia. Data of neonates was collected by direct interviewing of the mothers or other family members, clinical assessment and examination and relevant investigations were done.Results: The frequency of preterm neonatal thrombocytopenia was 95 (13.04%), out of 728 neonates admitted to neonatal care unit. Male to female ratio was 1.37:1, male gender was significantly associated with prematurity and mild to moderate severity thrombocytopenia (P 0.016, P 0.019). Prematurity was significantly associated with late onset neonatal thrombocytopenia (P 0.035). Late-onset thrombocytopenia, and 32- <37 wk gestational age group were significantly associated with mild to moderate severity thrombocytopenia group (P 0.008, and 0.004 respectively). Sepsis was a frequently associated risk factor in thrombocytopenic preterms, and found in 70 (73.68%) cases of preterm thrombocytopenia (with only 8 cases were culture positive and 62 cases were clinical based diagnosis). Also birth asphyxia, respiratory distress syndrome, and Rh incompatibility were significantly associated with thrombocytopenic prematures (P 0.026, 0.001, 0.008 and 0.036 respectively). Birth asphyxia, respiratory distress syndrome, sepsis and Rh incompatibility were significantly associated with moderate to severe thrombocytopenia (P 0.001, 0.001, 0.003 and 0.011 respectively). There was no significant difference between the presence of maternal disease and gestational age to the severity of neonatal thrombocytopenia (P 0.458, 0.698 respectively).Conclusions: Preterm thrombocytopenia is relatively common in neonatal care units. Sepsis, respiratory distress syndrome and birth asphyxia were significant neonatal risk factors of thrombocytopenia at lower gestational age preterms. Most episodes were late onset with mild or moderate severity.