The usefulness of culture medium selective in Group B Streptococcus at third-trimester screening

Abstract

 ［Objective］The purpose of this study was to consider the usefulness of culture medium selective in Group B Streptococcus（GBS）at third-trimester screening test in pregnancy.

 ［Methods］Since January 2022, we use the culture media selective in GBS at third-trimester screening test in pregnancy, and standardized the specimen collection sites to include vaginal openings and anus. We retrospectively compared the laboratory data of culture tests in 551 cases of delivery after third-trimester screening from January 2022 to December 2023（general medium plus selective medium group）, and 676 cases from January 2020 to December 2021（general medium only group）.

 ［Results］The GBS-positive rates of general medium only group and general medium plus selective medium group were 13.6％ and 20.9％, respectively, and significantly higher in the latter group（p＝0.00073）.

 ［Conclusion］We suggest that collecting specimens from the appropriate sites and using the GBS selective media can improve the sensitivity of GBS detection at the third-trimester screening.