Early-Onset Thrombocytopenia in Small-For-Gestational-Age Neonates: A Retrospective Cohort Study

<div><p>Thrombocytopenia is a common finding in small for gestational age (SGA) neonates and is thought to result from a unique pathophysiologic mechanism related to chronic intrauterine hypoxia. Our objective was to estimate the incidence and severity of early-onset thrombocytopenia in SGA neonates, and to identify risk factors for thrombocytopenia. We performed a retrospective cohort study of all consecutive SGA neonates admitted to our ward and a control group of appropriate for gestational age (AGA) neonates matched for gestational age at birth. Main outcome measures were incidence and severity of thrombocytopenia, hematological and clinical risk factors for thrombocytopenia, and bleeding. A total of 330 SGA and 330 AGA neonates were included, with a mean gestational age at birth of 32.9 ± 4 weeks. Thrombocytopenia (<150x10⁹/L) was found in 53% (176/329) of SGA neonates and 20% (66/330) of AGA neonates (relative risk (RR) 2.7, 95% confidence interval (CI) [2.1, 3.4]). Severe thrombocytopenia (21-50x10⁹/L) occurred in 25 neonates (8%) in the SGA and 2 neonates (1%) in the AGA group (RR 12.5, 95% CI [3.0, 52.5]). Platelet counts <20x10⁹/L were not recorded. Within the SGA group, lower gestational age at birth (p = <0.01) and erythroblastosis (p<0.01) were independently associated with a decrease in platelet count. Platelet count was positively correlated with birth weight centiles. In conclusion, early-onset thrombocytopenia is present in over 50% of SGA neonates and occurs 2.7 times as often as in AGA neonates. Thrombocytopenia is seldom severe and is independently associated with lower gestational age at birth and erythroblastosis.</p></div

Hematologic outcome.

<p>Hematologic outcome.</p

Predictors of platelet count in neonates with SGA.

<p>Predictors of platelet count in neonates with SGA.</p

Relationship between nucleated red blood cells in the first 3 days of life and birth weight centiles.

<p>Boxplot representing observed nucleated red blood cells (NRBC/100 white blood cells) in all included neonates (SGA and AGA, N = 653) in the first 3 days of life, categorized by birth weight centiles. Boxplot shows mean (black dots) and 95% confidence intervals (whiskers). Five missing values in SGA group, 2 in AGA group.</p