Fetal cell microchimerism: helpful or harmful to the parous woman?

Abstract
Fetal cells enter the maternal circulation during most pregnancies and can persist in maternal blood and tissues after delivery. Concerns with regard to the histocompatibility of these fetal cells have raised the question of the long-term consequences of an immune response on maternal health. In the past few years, many investigators have demonstrated an association between the persistence of fetal cells in maternal tissues and blood and maternal autoimmune disease, especially systemic sclerosis. In this review we will summarize more recent data that provide a new insight into bi-directional feto-maternal cell trafficking. Persisting fetal cells have been found in the tissue of women affected with endocrine or infectious disease as well as healthy parous women. These data suggest the possibility that fetal microchimeric cells may also participate in the maternal physiological response to tissue injury. The medical consequences of pregnancy, therefore, appear to extend well beyond delivery.