A practical approach to assessment of neonatal thrombocytopenia in NICU

Abstract

Objective: To study the occurrence, pattern, severity and outcome of neonatal thrombocytopenia based exclusively on the time of onset.

Methods: This retrospective study was performed at King Fahd Hospital of the University, a tertiary center for neonatal intensive care in Eastern Saudi Arabia.

Over a period of seven years (January 2000 to December 2006), all consecutive neonates admitted to NICU with at least two readings of platelet count of less than 150 × 10 $^9$ L were enrolled. The pattern of onset of thrombocytopenia was classified as early if it developed within the first 72 hours of age or late if it presented after that. Severity of thrombocytopenia was mild to moderate if the count was ⩾ 50 but < 150 × 10 $^9$ L and severe If < 50 × 10 $^9$ L. Time of resolution of thrombocytopenia was followed up retrospectively and grouped into weekly intervals. That is, if the time exceeds 4 weeks or a death ensues, the thrombocytopenia is labeled as unresolved.

Results: Out of 2592 neonates admitted to NICU during the study period, neonatal thrombocytopenia was diagnosed in 366 (14%). The onset was early in the majority (281, 77%) and late in the remaining 85 neonates. Mild to moderate thrombocytopenia was the diagnosis in 294 (80%) and severe in the rest.

Platelet count follow-up was obtained in 328 (90%), while 38 neonates (10%) had no subsequent count recorded. Slightly more than half of the followed neonates (170, 52%) had a normal platelet count by the end of the first week of life, while it normalized in 53 neonates (16%) within the second week, 17 (5%) in the 3rd, and 21 (6%) the 4th. week. For the remaining 67 (20%) neonates, they continued with unresolved thrombocytopenia.

Conclusions: Early onset neonatal thrombocytopenia occurs commonly in NICU populations regardless of gestational age with a benign course and a predictable outcome. The majority of the population of neonates in the current study had a mild to moderate thrombocytopenia, which reverted to normal within the first week in half of the affected neonates. On the other hand, late onset thrombocytopenia was mostly severe, recovery was delayed and half of the affected neonates had unresolved thrombocytopenia.

Keeping in mind the possibility of an overlap between the two patterns, neonatal thrombocytopenia which failed to conform to either pattern is likely to be a marker of significant pathology requiring more work up.