Thrombocytopenia in neonates with polycythemia: incidence, risk factors and clinical outcome

Abstract

Background: Polycythemia occurs in 1 to 5% of neonates and is associated with complications, including an increased risk of thrombocytopenia. Objective: To evaluate incidence, risk factors, management and outcome of thrombocytopenia in neonates with polycythemia. Study design: All neonates with polycythemia admitted to our neonatal intensive care unit between 2006 and 2013 were included in this retrospective study. We evaluated the incidence of thrombocytopenia (platelet count <150 × 10⁹/l) and severe thrombocytopenia (platelet count <50 × 10⁹/l) and the correlation between platelet counts and hematocrit values. Results: The incidence of thrombocytopenia and severe thrombocytopenia was 51 (71/140) and 9% (13/140), respectively. Platelet count was negatively correlated with hematocrit (spearman correlation coefficient −0.233, p = 0.007). After multiple regression analysis, we found an independent association between thrombocytopenia and being small for gestational age (OR: 10.0; 95%; CI: 1.2–81.7; p = 0.031). Conclusion: Thrombocytopenia occurs in 51% of neonates with polycythemia and is independently associated with growth restriction. Increased hematocrit is associated with decreased platelet count.

Keywords:

• growth restriction
• hyperviscosity
• neonates
• Polycythemia
• thrombocytopenia

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Neonatal polycythemia, defined as a venous hematocrit value of >65%, is a common problem and occurs in 1–5% of all live births.

• Neonatal polycythemia is associated with clinical and hematological complications, including an increased risk for thrombocytopenia.

• In this study with 140 polycythemic neonates, the incidence of thrombocytopenia (platelet count <150 × 10⁹/l) and severe thrombocytopenia (platelet count <50 × 10⁹/l) was 51% (71/140) and 9% (13/140).

• Thrombocytopenia in polycythemic neonates is mostly mild and self-limiting and is not associated with an increased risk of intraventricular hemorrhage.

• Platelet count was negatively correlated with hematocrit (spearman correlation coefficient -0.233, p = 0.007): that is, higher hematocrit is correlated with a lower platelet count.

• Logistic regression analysis shows that growth restriction is the only independent causative factor associated with thrombocytopenia in polycythemic neonates.