I have no idea about those in particular, but I now know random infections can get in there. I never would have thought it was possible except for the big ones, but my baby died from some unknown infection that managed to get into the placenta. Totally random event and not very common at all, but it did happen. The only thing they could find wrong with me in any way was that there was a viral type infection in the placenta, but it wasn't any of the ones they usually look for. They tested me, the baby, and the placenta for all of the big infections, but it wasn't one of those. It was just listed as "placental infection" or something like that, but they did not know the strain.