Very/extremely low birth weight infants (VLBWI/ELBWI) have a common need for red blood cell transfusion (RBCT) within 28 days after birth. The current controversy centers on the selection of the transfusion threshold strategy, with a lack of in-depth discussion on the frequency of red blood cell transfusion and the correction for disease severity.

This study aimed to explore the relationship between the frequency of blood transfusion within 28 days after birth for very low birth weight infants (VLBWI) and adverse outcomes (severe complications and in-hospital death).

A retrospective analysis was conducted on the data of 408 very low birth weight infants and extremely low birth weight infants admitted to the Neonatal Intensive Care Unit of Zhangzhou Hospital Affiliated to Fujian Medical University from 2018 to 2020.Based on the results of RBCT, 408 infants were divided into the blood transfusion group (303 cases) and the no-blood-transfusion group (105 cases). Compare the clinical characteristics and adverse outcomes of the two groups of children [at least one of the following complications must occur, including retinopathy of prematurity (ROP)>stage 2, moderate to severe bronchopulmonary dysplasia (BPD), and in-hospital death]. Spearman rank correlation analysis was used to explore the relationships between gestational age at birth (GA), birth weight (BW), and complications (delivery room intubation, mechanical ventilation for more than 5 days, confirmed sepsis, grade 3-4 periventricular-intraventricular hemorrhage) and the number of blood transfusions. Multivariate Logistic regression analysis was used to assess the associations between GA, BW, comorbidities and the number of blood transfusions and the occurrence of adverse outcomes in VLBWI and extremely low birth weight infants (ELBWI).

Among the 408 infants, 256 were male (62.7%) and 152 were female (59.3%). The average gestational age was (29.8±2.1) weeks and the average birth weight was (1 205±248) grams. Among them, 303 cases (74.3%) of the infants underwent RBCT within 28 days after birth. There were statistically significant differences (P<0.05) between the transfusion group and the non-transfusion group in terms of GA, BW, 5-minute Apgar score, small for gestational age (SGA), delivery room intubation, mechanical ventilation >5 days, confirmed sepsis, grade 3-4 periventricular-intraventricular hemorrhage, ROP >stage 2, moderate to severe BPD, and in-hospital death. The results of the correlation analysis showed that GA and BW were negatively correlated with the number of blood transfusions (r_s=-0.544, P<0.001; r_s=-0.541, P<0.001), while complications were positively correlated with the number of blood transfusions (r_s=0.385, P<0.001). The results of the multivariate Logistic regression analysis showed that GA≥30 weeks (OR=0.482, 95%CI=0.281-0.827, P=0.008) and BW≥1 250 g (OR=0.447, 95%CI=0.261-0.765, P=0.003) were protective factors for adverse outcomes in VLBWI/ELBWI, while having complications (OR=1.868, 95%CI=1.138-3.066, P=0.013) and the number of blood transfusions ≥3 times (OR=3.275, 95%CI=1.707-6.275, P<0.001) were risk factors for adverse outcomes in VLBWI/ELBWI.

Receiving RBCT within 28 days after birth is relatively common in VLBWI/ELBWI cases (74.3%), and factors such as GA<30 weeks, BW<1 250 g, presence of complications, and ≥3 blood transfusions may be independent risk factors for severe complications and in-hospital mortality. It is suggested that ≥3 blood transfusions within 28 days be used as a high-risk warning sign for VLBWI/ELBWI, and for infants with ≥3 blood transfusions, intensified monitoring of complications should be carried out to improve prognosis.