We sought to determine the pathway through which syngeneic hematopoietic stem cells (HSCs) delivered into the amniotic fluid can reach the fetal circulation.
Lewis rat fetuses were divided in two groups based on the content of intra-amniotic injections performed on gestational day 17 (E17; term=E21-22): either a suspension of luciferase-labeled syngeneic HSCs (n=137), or acellular luciferase (n=44). Samples from placenta, chorion, amnion, amniotic fluid, umbilical cord, and 8 fetal sites were procured at 5 daily time points thereafter until term for analysis.
When controlled by acellular luciferase, donor HSCs were identified in the amnion, chorion, placenta, and amniotic fluid of fetuses receiving cells at all time points (p=0.033 to
