A total of 349 pregnant women were included in the study. A nurse collected vaginal secretions from the vaginal introitus using a sterile cotton swab. The vaginal swab was inoculated at the clinic in the upper-chamber of an InPouch system (BioMed Diagnostics, White City, Oregon, USA). The inoculated InPouch was transferred to the laboratory within 15 min for direct microscopy of the upper chamber, after which it was merged with the lower chamber and incubated at 37 ± 1 °C under aerobic conditions. Daily microscopic observation of the InPouch system was performed and media with motile trichomonads within 5 days of culture were considered positive for T. vaginalis. Two ml of the contents of each InPouch system positive for T. vaginalis were transferred into a 2.0 ml Eppendorf tube and stored at -80 °C until shipment to the Laboratory of Bacteriology Research (Ghent University, Belgium) using shipping boxes filled with dry ice (-78.5 °C). The samples were stored at -80 °C until molecular analysis was performed.