Figure 1. Distribution of Platelet Counts Prior to First Platelet Transfusion in Preterm Infants.

Infants who received prophylactic transfusions (a transfusion that occurred before any intraventricular hemorrhage) and with platelet count results within 24 hours prior to the transfusion were selected. If multiple platelet count records existed within 24 hours prior to transfusion, the lowest value was selected. To convert platelet count to ×10⁹ per liter, multiply by 1.