Birthweight of full-term infants is associated with cord blood CD34+ cell concentration

Aim: CD34(+) cell counts are used to define the haematopoietic stem cell potential of a given cord blood transplant. The aim was to test the hypothesis that high concentration of cord blood haematopoietic progenitor and stem cells could be a reflection of intrauterine growth, of which birthweight is an indicator. Methods: Simple and multiple regression analyses were applied to test cord blood bank data on 1368 infants for associations of selected obstetric factors and cellular contents of cord blood. Results: When groups were formed based on the extreme values (5th versus 95th percentiles) of a given variable, e.g. birthweight, the term infants having the highest birthweights were found to have statistically significantly higher median cord blood CD34(+) cell concentrations. Also, infants in the top 50th percentile of relative birthweight had higher median CD34(+) cell concentration than infants in the low 50th percentile. In multiple regression analysis, the correlation between birthweight and CD34(+) cell concentration was statistically clearly significant. Notably, while an expected correlation between gestational age and nucleated cell concentration was found, there was no association between infant gestational age and CD34(+) cell concentration. Conclusion: Haematopoietic progenitor and stem cells may reflect intrauterine growth and have a more central role in foetal development than has been reported earlier.