Early life processes, through influence on fetal stem cells, affect postnatal and adult health outcomes. This study examines effects of physical activity before and during pregnancy on stem cell counts in umbilical cord blood.
We isolated mononuclear cells from umbilical cord blood samples from 373 singleton full-term pregnancies and quantified hematopoietic (CD34, CD34CD38, CD34c-kit), endothelial (CD34CD133, CD34CD133VEGFR2, CD34VEGFR2, and CD133VEGFR2), and putative breast (EpCAM, EpCAMCD49f, EpCAMCD49fCD117, CD49fCD24, CD24CD29, and CD24CD29CD49f) stem/progenitor cell subpopulations by flow cytometry. Information on physical activities before and during pregnancy was obtained from questionnaire. Weekly energy expenditure was estimated based on the metabolic equivalent task (MET) values.
Pre-pregnancy vigorous exercise was associated positively with levels of the endothelial CD34CD133, CD34CD133VEGFR2, CD34VEGFR2, and CD133VEGFR2 progenitor cell populations (p=0.02, 0.01, 0.001, and 0.003, respectively); the positive associations were observed in samples from the first births and those from the second or later births. Pre-pregnancy moderate and light exercise and light exercise during the first trimester were not significantly associated with any stem/progenitor cell population. Light exercise during the second trimester was positively associated with CD34VEGFR2 endothelial progenitor cells (p=0.03). In addition, levels of the EpCAMCD49f and CD49fCD24 breast stem cells were significantly lower among pregnant women who engaged in vigorous or moderate exercise during pregnancy (p=0.05 and 0.02, respectively).
Vigorous exercise before pregnancy increases endothelial progenitor cell numbers in umbilical cord blood and thus could potentially enhance the endothelial function and improve cardiovascular fitness in the offspring. Findings of a lower level of putative breast stem cell sub-populations could have implication on exercise and breast cancer prevention. Prenatal effects of exercise on fetal stem cells warrant further studies.