721 - Association Between Platelet Transfusion and Neurodevelopmental Outcomes at 36 Months Age in Preterm Infants Born Before 29 Weeks’ Gestation

Publication Number: 2703.721

Marika Grant, University of Calgary, Calgary, AB, Canada; Majeeda Kamaluddeen, University of calgary, Calgary, AB, Canada; Amuchou Soraisham, University of Calgary, Calgary, AB, Canada; Amina Benlamri, university of calgary, calgary, AB, Canada; Andrew Walker, Alberta Health Services, Calgary, AB, Canada; Sue Makarchuk, Alberta Health Services, Calgary, AB, Canada; Selphee Tang, Alberta Health Services, Calgary, AB, Canada; Abhay Lodha, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada

Background: Adult platelet are frequently transfused to preterm infants and have been associated with an increased risk of neurodevelopmental impairment (NDI) and mortality at 18-24 months corrected age (CA). However, evidence regarding neurodevelopmental outcomes at 36 months CA remains limited in premature infants.

Objective: To determine the association between platelet transfusion and death or severe NDI at 36 months CA in premature infants born < 29 weeks' gestation.

Design/Methods: In this retrospective cohort study, all infants born before 29 weeks' gestation between 2005 and 2019, who were followed in the regional neonatal follow-up clinic and underwent neurodevelopmental assessments at 36 months CA, were included. Infants were divided into two groups: Group I: Infants who did not receive any platelet transfusions and Group 2: Infants who received ≥1 platelet transfusion. The primary outcome was a composite of death or severe NDI. Severe NDI was defined as a Full-Scale IQ (FSIQ) score >2 standard deviations (SD) below the mean on standardized testing (WPPSI-III or IV), moderate to severe cerebral palsy (CP), bilateral blindness (corrected visual acuity of < 20/200 in the better eye), or bilateral sensorineural hearing loss requiring amplification or cochlear implants. Univariate analysis, multivariable logistic regression, and propensity score matching were used to adjust for confounding variables.

Results: Of 1692 eligible infants, 1443 (85%) were followed up, (Group I: 1214, received no platelets transfusion and Group II: 229, received ≥1 platelet transfusions, Figure 1). Group I and Group II had median birthweights (IQR) of 899g (730-1065) and 724 g (600-840) (p < 0.001) and median GAs (IQR) were 27(25-28) and 25 (24-27 (p < 0.001) respectively (Table 1). The adjusted odds of death or severe NDI and cognitive delay (>1 SD below mean) at 36 months CA in infants who received platelets transfusion were 1.60 (95% CI 1.06-2.40) and 1.76 (1.14-2.72) respectively (Table 2).

Conclusion(s): In preterm infants born before 29 weeks' GA, platelet transfusion was associated with an increased risk of the composite outcome of death or severe NDI and cognitive delay at 36 months CA. These findings support a restrictive transfusion strategy in non-bleeding premature infants.

Patient Flowchart


Maternal and Neonatal characteristics
*Chi-squared or Fisher's exact test for categorical variables; Wilcoxon rank sum test for continuous variables
a Includes conventional, HFOV, jet, oscillator
b This may be over-estimated for birth years prior to 2010, as days on invasive ventilation and CPAP were included together prior to 2010 while from 2010 onward only days on invasive ventilation were counted.

Neurodevelopmental Outcomes at 36 Months Corrected Age
OR: odds ratio for ≥1 platelet transfusions vs. no platelet transfusions; CI: confidence interval; NDI: neurodevelopmental impairment; SD: standard deviation; GMFCS: Gross Motor Function Classification System.
*Chi-square or Fisher's exact test.
†Model not fit due to small number of events.
1 Adjusted for: gestational age, SGA, maternal antihypertensives, inborn, intubation and/or chest compression at birth, nec, sepsis, and SNAP II score. Also adjusted for maternal education for outcomes not involving death.
2 Propensity score estimated using a logistic regression model using gestational age, SGA, maternal antihypertensives, inborn, intubation and/or chest compression at birth, NEC, sepsis, and SNAP II. Also adjusted for maternal education for outcomes not involving death. There were 218 matched pairs in each group.
$ Definition of Any NDI: was defined as FSIQ score >1 SD below the mean on standardized testing (WPPSI-III/IV), mild to moderate-severe cerebral palsy, visual impairment (between 20/60 and 20/200 in the better eye, significant myopia, hypermetropia, or unilateral blindness) or bilateral blindness (corrected visual acuity of <20/200 in the better eye), or sensorineural hearing loss.