Synthesis of Results
After data extraction, the included studies were divided into two groups: GBS reported and GBS not reported. Independent t-tests were conducted to compare the number of pregnant women and the number of vaginal specimens between GBS reported and not reported groups. The commonalities and differences among 16S rRNA primer regions used were compared. We then qualitatively compared the commonalities and differences of the other methodological categories between two groups, since methods were too varied to compare statistically.