Interesting article suggest these microbes may be pathogenic.
[1]References
- K.B. Waites, R.L. Schelonka, L. Xiao, P.L. Grigsby, and M.J. Novy, "Congenital and opportunistic infections: Ureaplasma species and Mycoplasma hominis", Seminars in Fetal and Neonatal Medicine, vol. 14, pp. 190-199, 2009. http://dx.doi.org/10.1016/j.siny.2008.11.009