It is thought that some women who experience recurrent unexplained miscarriages are fighting against their own bodies. These women have overactive immune systems that attack new cells, including those that would become fetuses. According to a study done in Liverpool, a sample of these women showed good outcomes when treated with a once a month steroid pill usually used to treat allergies and asthma. Trials continue to investigate the validity of the treatment and the effect on the children brought to term with the use of these steroids.
I'm interested to see how this turns out. Overactive immune system was one of the many thoughts I had when I was having miscarriages.