Just in time for Mother's Day, Nancy Shute at Scientific American writes about new research that shows that bits of a baby's genetic material can be passed along to the mother during pregnancy, and that the cells that linger after the birth can influence the woman's risk of getting cancer, rheumatoid arthritis, or other diseases. "All pregnant women carry some fetal cells and DNA," Shute says, "with up to 6 percent of the free-floating DNA in the mother's blood plasma coming from the fetus." When the baby is born, those numbers go down, but the cells don't disappear entirely. Researchers exploring this phenomenon – fetal microchimerism – found fetal cells in women with scleroderma and systemic sclerosis, Shute says. More recent studies suggest that the cells could actually protect a woman against arthritis. These are all autoimmune diseases, Shute adds, and all of these effects may be caused by the mother's immune response to the child's cells. Mothers with fetal cells in their blood also have a lower risk of breast cancer than mothers who don't, studies suggest. "The immune response triggered by fetal cells might help the body detect cancer cells later in life," Shute says. However, lingering fetal cells have been shown to increase the risk of cancer in other tissues. "Researchers don’t know what fetal cells are doing in tumors, but they aren’t prepared to give the cells a clean bill of health," Shute adds. But fetal cells have been shown to migrate to injury sites and help in healing. Because they are stem cells, the mother's body may be actively recruiting them to aid in healing, Schute reports.
Some Cells for Mom
May 07, 2010