Clinical Characteristics, and Outcomes of Severe Neonatal Thrombocytopenia: a Retrospective Cohort Study in China

Background: Severe neonatal thrombocytopenia, as a rare but life-threatening disease with multiple etiologies, has limited relevant reports in China. The single-center study was performed in a severe thrombocytopenic cohort to improve the prognosis of this disease. Methods: We included all the patients diagnosed with severe thrombocytopenia (platelet counts £ 50×10 ³ /μL) in our institution between October 2016 and February 2021, and retrospectively reviewed their electronic records. Comparisons were made according to etiology and outcome. Results: Among the 5819 inpatients, 194 with severe thrombocytopenia were included in this study, with 64.4% of the cases occurring within 72 hours of life. The highest incidence was recorded among extremely low birth weight neonates (6.5%). The main etiologies included sepsis (22.2%), genetic syndromes (14.4%), perinatal asphyxia (9.8%), necrotizing enterocolitis (NEC; 8.8%), and cytomegalovirus infection (6.7%). The mean (SD) platelet nadir was 26.0 (14.0) × 10 ³ /μL, and 112 patients developed very severe thrombocytopenia (platelet counts £ 30×10 ³ /μL), of which 21.4% were caused by late-onset sepsis. In 45 culture-positive cases, the gram-negative group had a lower level of platelets (mean [SD]: 28 [11]×10 ³ /μL) as compared to the gram-positive group (mean [SD]: 39 [12]×10 ³ /μL). A total of 120 cases (61.9%) exhibited evidence of hemorrhage, with patients diagnosed with NEC demonstrating the highest incidence of hemorrhage at 58.8%. The platelet counts took a median of 10 days to recover: 11 and 7 days for early and late-onset cases; 15 days without and 21 days with platelet transfusions, respectively. The overall mortality rate was 26.8%. The causes of severe thrombocytopenia in 32.7%, 19.2%, and 17.3% of patients who died were identified as sepsis, birth asphyxia, and NEC, respectively. The levels of PT ( P = 0.025), APTT ( P = 0.046), and lactate ( P = 0.028) were lower among surviving patients. Conclusions: Sepsis, genetic syndromes, and perinatal asphyxia are the predominant etiologies of severe neonatal thrombocytopenia in China. The overall prognosis of severe neonatal thrombocytopenia is poor, but its severity and short-term prognosis can be determined by relevant laboratory tests and the etiology.