[Bidirectional cell traffic between mother and fetus: new insights in pediatric and adult disorders].

There is a heavy traffic of cells and DNA through the placenta during pregnancy. The rate of fetal cells in the maternal blood is correlated with abnormalities, such as aneuploidy and pre-eclampsia. Studying and quantifying these cells could improve antenatal diagnosis techniques, especially for Down syndrome. Maternal-fetal microchimerism is frequently observed in several auto-immune diseases in adulthood, such as systemic scleroderma. Studies suggest a rather allo-immune pathophysiology, involving maternal-fetal HLA compatibility. Microchimerism is also found in auto-immune diseases in children. Thus, the cells traffic offers new insights for antenatal diagnosis techniques and pathophysiology of auto-immune diseases.