The study has started 2007 and will continue until 2014. Pregnant women that will come to the maternal health care units in gestational week 8-11 will be offered to be screened for bacterial vaginosis. A vaginal sample will be taken by the midwife or by the women herself. The vaginal sample is air-dried and sent to the gynecological. There it is investigated using Hay/Ison classification for the diagnosis of bacterial vaginosis.