[1] Akershus Univ Hosp, Dept Obstet & Gynecol, N-1478 Lorenskog, Norway
[2] Univ Oslo, Fac Med, N-0316 Oslo, Norway
[3] Norwegian Inst Publ Hlth, Div Mental Hlth, Oslo, Norway
[4] Ullevaal Univ Hosp, Dept Microbiol, Oslo, Norway
[5] Asker & Baerum Hosp, Dept Microbiol, Baerum, Norway
[6] Ullevaal Univ Hosp, Dept Obstet & Gynecol, Oslo, Norway
[7] Harvard Univ, Sch Med, Boston, MA USA
[8] Massachusetts Gen Hosp, Dept Med, Renal Unit, Boston, MA 02114 USA
[9] Beth Israel Deaconess Med Ctr, Dept Med Obstet & Gynecol, Boston, MA 02215 USA
[10] Norwegian Univ Sci & Technol, Dept Publ Hlth, N-7034 Trondheim, Norway