Neonatal Platelet Transfusion Threshold Trial

Thrombocytopenia, defined as a platelet count \<150 x 10\^9/L, is a common neonatal problem that affects 22% to 35% of infants admitted to the neonatal intensive care unit. Platelets are important for primary hemostasis to prevent blood extravasation after vascular injury. Based on the role of platelets in hemostasis, prophylactic platelet transfusions are routinely administered to preterm infants with thrombocytopenia to prevent bleeding. The incidence of thrombocytopenia and administration of platelet transfusion are both inversely related to the gestational age at birth. Currently, there is uncertainty regarding the optimal platelet transfusion threshold, particularly among the most immature infants in the first week of life, which represents the period of highest bleeding risk.

The NeoPlaTT trial was designed to address this pressing uncertainty in the highest risk population (\<27 weeks GA). It will test whether a threshold of 20x10\^9/L could be safely used after the first week of life, when the risk of serious bleeding is significantly lower, and reduce the need for platelet transfusion altogether. The results of this study have a potential to change clinical practice and improve outcomes in this vulnerable population, while also decreasing costs and resource utilization.

This is a randomized trial with 1:1 allocation to parallel arms. Infants, inborn or outborn, who are admitted to participating NICUs, and who meet the inclusion and exclusion criteria, will be invited to enroll into the trial for platelet count monitoring. Only consented and enrolled infants meeting the additional platelet count trigger of \< 50 x 10\^9/L (postnatal days 1-7) or \<35 x 10\^9/L (8 or more postnatal days) will be randomized. Postnatal day 1 starts at birth. Randomization will be allowed to occur up to 36 6/7 weeks' PMA; subjects will be monitored through 40 0/7 weeks PMA. Approximately 30% of consented and enrolled infants are expected to meet the platelet count threshold for randomization.

• Death [Срок оценки: Randomization to 52 0/7 weeks' postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first, per Neonatal Research Network Generic Research Database Registry protocol.]
• Major or severe bleeding [Срок оценки: Randomization to 40 0/7 weeks postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first (an average of 98 days postnatal age)]
• Number of platelet transfusions [Срок оценки: Randomization to 40 0/7 weeks postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first (an average of 98 days postnatal age)]
• At least one platelet transfusion [Срок оценки: Randomization to 40 0/7 weeks postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first (an average of 98 days postnatal age)]
• Bronchopulmonary dysplasia among survivors to 36 weeks postmenstrual age [Срок оценки: At 36 weeks postmenstrual age]
• Retinopathy of Prematurity (ROP) [Срок оценки: Randomization to 52 0/7 weeks' postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first, per Neonatal Research Network Generic Research Database Registry protocol.]
• Periventricular leukomalacia [Срок оценки: Randomization to 52 0/7 weeks' postmenstrual age, death, discharge, or transfer outside of the Study Center, whichever occurs first, per Neonatal Research Network Generic Research Database Registry protocol.]