Evaluation of ex‐utero collection for umbilical cord blood banking: A randomized clinical trial comparing cord blood quality with the in‐utero technique

Background Umbilical cord blood (UCB) can be collected in utero (before placental delivery) or ex utero (after placental delivery). While in utero collection is standard, ex utero collection is less intrusive during birth and better tolerated by mothers. However, its efficiency remains unclear. Objective(s) The primary objective was to demonstrate that ex utero umbilical cord blood (UCB) collection is non‐inferior to in utero collection in terms of UCB unit weight, as a surrogate of collected volume. Secondary objectives were to confirm that progenitor cells obtained ex utero meet established quality criteria and that the method yields a lower rate of bacterial contamination. Study Design We conducted a prospective, unblinded, randomized clinical trial (from September 2023 to September 2024) at Hospital Universitari Dexeus and with the Concordia Cord Blood Program in Barcelona (Barcelona Cord Blood Bank) registered at ClinicalTrials.gov (Identifier: NCT05836974). Pregnant women were randomized 1:1 to ex utero or in utero collection. In the experimental arm, UCB was collected after placental delivery on a surgical table; in the control arm, collection occurred before placental delivery. In both arms, the cord was clamped 1 min after birth. A minimum UCB weight of 85 g was required. They were then distributed for further processing in: (i) research biobank/culture media (85–100 g); (ii) multicomponent use (>100 g with <1.5 × 10 9 nucleated cells); or (iii) transplantation (>100 g with >1.5 × 10 9 nucleated cells). Secondary endpoints included total nucleated cell (TNC) count, red blood cells count, hematocrit, platelets, and bacteriology, assessed only in units designated for clinical use. Results Of 133 patients screened, 129 were randomized. Following exclusions (10 in the in utero group and 18 in the ex utero group), a total of 53 in utero collections and 48 ex utero collections were analyzed. Baseline characteristics, including maternal age, gestational age, type of delivery, and newborn gender, were similar. The mean weight of the UCB was 107.19 ± 29.51 g ex utero and 110.81 ± 29.62 g in utero, resulting in a mean difference of −3.62 g (95% confidence interval [CI] −13.41; 6.16 g). The proportion of UCB units below 85 g was comparable between the groups. Both methods showed a similar distribution pattern. Bacteriology (number of samples tested were 35 in utero, 22 ex utero) yielded one positive culture in each group. Total nucleated cell counts, red blood cell counts, and hematocrit and platelet counts did not differ significantly between collection methods. Conclusion(s) Ex utero UCB collection is non‐inferior to the standard in utero method in terms of UCB weight, cellular composition, and contamination rates. With standardized procedures, ex utero collection is a clinically viable alternative to facilitate umbilical cord blood donations. Date of registration : 19th April 2023. Date of initial participant enrollment : 1st September 2023. Clinical trial identification number : NCT05836974. URL of the registration site: ClinicalTrials.gov .