CBUs characteristics
The analyses of CBUs collected and processed at InScientiaFides from July 2016 to June 2021 (study sample) demonstrated that the 51.06% of the CBU collected derived from males, while the remaining 48.93% from females. Furthermore, the majority of samples resulted from vaginal (62.95%) compared to 36.43% of caesarean deliveries, respectively, with a median birth weight of 3.17 kg (range,1.02–5.04 kg). The majority of pregnant women give birth at 39 (median value with a range 30–45) weeks of gestation with a median age of 38 years (range 20–58 years). The demographic Italian analysis showed that 40.81% of the samples come from the north of Italy, while 27.84%, 21.45% and 9.81% from the center, south and islands, respectively. In addition, the birth distribution of our series in the various seasons was 23.23% in winter, 27.91% in autumn, 24.47% in spring and 24.51% in summer (Table 1).
Table 1
Clinical characteristics of maternal and infant CBU.
| N (%) | Median (range) | Mean (± SD) |
Number of CBU collected | 2583 (100%) | | |
Babies’ gender | | | |
Male | 1319 (51.06%) | | |
Female | 1264 (48.93%) | | |
Infant gestational age (weeks) | | 39 (30–45) | 39.09 (± 1.34) |
Maternal age (years) | | 38 (20–58) | 37.56 (± 5.42) |
Birth weight (kilograms) | | 3.17 (1.02–5.04) | 3.29 (± 1.23) |
Type of delivery | | | |
Caesarean | 941 (36.43%) | | |
Vaginal | 1555 (62.95%) | | |
Geographical birth area (Italy) | | | |
South | 554 (21.45%) | | |
Islands | 256 (9.91%) | | |
Center | 719 (27.84%) | | |
North | 1054 (40.81%) | | |
Season of birth | | | |
Spring | 632 (24.47%) | | |
Summer | 633 (24.51%) | | |
Autumn | 721 (27.91%) | | |
Winter | 600 (23.23%) | | |
The clinical characteristics of the samples were the following: the CBUs collected had a median volume of 72 ml (range, 15–205 ml) with a median time to processing from birth to freezing of 43 hours (range, 6–127 hours). After processing, the CBUs median TNC and CD34 + content were 3.44 x108 (range, 2.40 x106 – 18.83x109) and 7.69 x 105 (range, 2.40 x 103 – 1.35x107), respectively. Post-process CD34 + viability was, on overage, 95.1% while the analysis of CB blood group showed that 44.25% of babies had 0 blood group respect to the 36.93%, 10.84% and 3.25% A, B and AB group, respectively (Table 2).
Table 2
Characteristics of the processed cord blood units including post-processing cellular content.
| N (%) | Mean (± SD) | Median (range) |
Number of CBU collected | 2583 (100%) | | |
Collection volume (ml) | | 74.46 (± 26.54) | 72 (15–205) |
Time to processing from birth to freezing (hours) | | 43.67 (± 14.66) | 43 (6-127) |
CBU TNC count (x 108) | | 3.86 (± 2.14) | |
3.44 |
(0.002–88.3) |
CBU CD34 + count (x 106) | | 1.14 (± 1.18) | |
0.769 |
(0.0002- 13.5) |
CD34+Viability (%) | | 95.10 | |
Blood group of babies: | | | |
A | 954 (36.93%) | | |
B | 280 (10.84%) | | |
0 | 1143 (44.25%) | | |
AB | 84 (3.25%) | | |
Post process CBU analyses
A first set of single-regression analysis strongly confirms in our large-series CBU (study sample) the correlation previously reported by us [11] between CBU TNC and CD34+ (r = 0. 5368, p < 0.001), TNC and CBU volume (r = 0. 5149, p < 0.001) and between volume and CD34+ (r = 0. 3175, p < 0.001). A regression analysis between CD45 + cells and TNC count was performed to confirm the accuracy of our TNC count, showing high correlation with TNC (r = 0.8022, p < 0.001) (Fig. 1).
Maternal and prenatal data analyses
Taking into account the gestational age, we found a positive correlation with CBU TNC content (r = 0.0213, p = 0.0001) while no correlations were found with CD34 + and volume (r = 0.00008, p = 0.65; and r = 0.0008, p = 0.15, respectively). No correlations were obtained for TNCs and CD34 + content with mother age (r = 0.0006, p = 0.198; r = 0.002, p = 0.442, respectively) while significant was the correlation with volume (r = 0.0024, p = 0.013,) and mother age. Then, we confirmed the correlation between birth weight and CD34+ (r = 0.0772, p < 0.005), also showing significant as well as correlation of birth weight with TNC and volume (r = 0.1152, p < 0.005 and r = 0.1024, p < 0.005, respectively) (Fig. 2).
One-way ANOVA analyses showed that child gender affects CBU TNC content while birth modality affects only the CBU volume. Particularly, females (3.97x108 ± 2.2x108) showed a higher TNC content than males (3.75 x108 ± 2.2x108). Concerning the type of delivery, it influences CBU volume only: cesarean deliveries showed higher volumes (79.76 mL ± 28 mL) compared to vaginal (71.06 mL ± 24.47 mL) (Fig. 3).
The blood group of the child did not show any correlation with sample characteristics considering TNC, CD34 + and CBU volume (Data not shown).
Seasonal and geographical data analyses
The birth seasonal analyses demonstrated that the CBU volume collected in winter and autumn (76.71 mL ± 28.23 mL for winter and 75.63 mL ± 25.84 mL for autumn, on average) are more abundant than those collected in the hot months (71.74 mL ± 24.12 mL for spring, and 73.82mL ± 26.11 mL for summer, on average)(Fig. 4). No significant differences were observed in TNC and CD34 + amount during the seasonal analysis. Finally, the evaluation of Italian geographical area showed (Fig. 4) that samples collected in the middle-south have higher volumes and higher TNC/CD34 + content than those of north area. For CBU collected in islands, we did not observe any significant difference for TNC and CD34 + counts as compared to the rest of Italy, while lower volumes were observed as compared to CBU collected in the middle-south.
Multivariate analyses
In order to determine the best predictor of CBU quality, a multivariate analysis was performed taking into account the influence of maternal, pre and postnatal data, as well as geographical and seasonal data. As highlighted in Table 3, the independent variables explain 71% of the variability of the content of TNC (p = 0.000).
Table 3
Clinical characteristics predictive of TNC content in multiple regression analyses.
Donor-related variables | Standardized Coefficients β | t | p-value |
SEX c | -0.06 | -6.08 | 0.000 |
GESTATIONAL AGE | 0.15 | 14.01 | 0.000 |
DELIVERY METHOD d | 0.10 | 8.30 | 0.000 |
VOLUME | 0.45 | 35.16 | 0.000 |
GEOGRAFICAL AREAe | 0.00 | 0.13 | 0.899 |
CD34+ | 0.49 | 37.74 | 0.000 |
SEASONf | 0.00 | -0.27 | 0.790 |
MOTHER AGE | 0.01 | 0.71 | 0.478 |
BIRTH WEIGHT | -0.01 | − .48 | 0.633 |
Significant correlation are shown in bold. |
c Female as the reference group
d Cesarean delivery as the references group
e South as the references group
f Winter as the references group
The content of CD34+ (p = 0.000) and volume (p = 0.000) are the main factors that positively influenced the CB TNC content, as well as delivery method (p = 0.000), gestational age (p = 0.000) and babie’s gender (p = 0.000), (vaginal higher than cesarean, higher gestational age higher than lower, females higher than males). The independent variables considered in multiple regression explain 56% of the variability of the CD34 + content (p = 0.000). TNC count represents the most important variable that influenced the CD34 + cells. The gestational period had negative correlation with the CD34 + cell content (p = 0.000). Concerning type of delivery (p = 0.004) and babie’s gender (p = 0.000), we found that cesarean delivery and male infants increase the CD34 + cells content (Table 4).
Table 4
Clinical characteristics predictive of CD34 + content in multiple regression analyses.
Donor-related variables | Standardized Coefficients β | t | p-value |
SEX c | 0.07 | 5.14 | 0.000 |
GESTATIONAL AGE | -0.09 | -6.23 | 0.000 |
DELIVERY METHOD d | -0.04 | -2.91 | 0.004 |
VOLUME | 0.02 | 0.91 | 0.362 |
GEOGRAFICAL AREA e | -0.01 | − .91 | 0.364 |
TNC | 0.74 | 37.01 | 0.000 |
SEASON f | 0.00 | -0.21 | 0.831 |
MOTHER AGE | -0.02 | -1.32 | 0.189 |
BIRTH WEIGHT | 0.02 | 1.48 | 0.140 |
Significant correlation are shown in bold. |
c Female as the reference group
d Cesarean delivery as the references group
e South as the references group
f Winter as the references group
In order to validate our results, a predictive model based on results of our multivariate analyses was built using the CBUs data collected from July to December 2021 (test samples; see Materials and Method). T- student test results highlighted that CD34 + content of group A (male babie’s, gestational age lower to 39 weeks, cesarean delivery and CBUs with a content of TNC higher than 3.44x 108 ) was significant higher than group B (female babie’s, gestational age higher than 39 weeks, vaginal delivery and a count of CBUs TNC lower to 3.44x 108) (t-value = 7.18; p < .00001); in addition 37.5% of CBUs had a CD34 + content > 2x106 in group A, while no CBUs with a content of CD34 + > 2x106 was detected in group B (Table 5).
Table 5
Application of the predictive model on the test CBU sample.
| GROUP A (± SD) | GROUP B (± SD) | p-value |
N° | 36 | 144 | - |
CD34 + mean (x 106) | 1.63 (± 0.78) | 0.44 (± 0.27) | < .00001 |
Frequency of CB with CD34 + > 2x106 | 37.5% | 0% | - |
Comparison of CBU of group A (male babie’s, gestational age lower to 39 weeks, cesarean delivery and CBUs with a content of TNC higher than 3.44x 108) versus group B (female babie’s, gestational age higher than 39 weeks, vaginal delivery and a count of CBUs TNC lower to 3.44x 108). |