Maternal and Neonatal Factors Impacting the Volume and Cellular Composition of Umbilical Cord Blood

Umbilical cord blood (UCB) is a well-established source of hematopoietic stem cells (HSCs) for transplantation, with over 30 years of clinical experience confirming its safety and efficacy. However, the limited cell count contained for a single UCB unit remains a major constraint on its application in adult recipients, and donor eligibility criteria vary greatly among different cord blood banks. This study aimed to identify key maternal, neonatal, and perinatal factors that influence the volume and quality of collected UCB to help overcome this limitation. We conducted a retrospective analysis of 229 UCB units voluntarily donated by pregnant women at our hospital. Correlations between UCB parameters and a range of clinical characteristics were evaluated. Maternal body mass index (BMI), umbilical cord length, and UCB oxygen partial pressure (pO 2 ) were independently associated with UCB volume and cellular parameters. Furthermore, umbilical cord length and maternal platelet-to-lymphocyte ratio (PLR) showed associations with TNC count in univariate analysis, although no independent factors were identified after multivariable adjustment. The CD34 + /TNC ratio was independently associated with umbilical cord length, gestational age, maternal total cholesterol level, placental weight, and UCB pH value. Finally, umbilical cord length was independently associated with the total CD34 + cell count. These findings provide preliminary evidence that selected maternal, neonatal, and perinatal characteristics are associated with UCB volume and cellular parameters. Further multicenter studies incorporating functional stem-cell assessments and transplantation outcomes are required before changes to donor eligibility or UCB unit-selection criteria can be considered.