Ma'ayeh M, et al. - Researchers compared women using intravaginal progesterone suppositories vs those receiving intramuscular 17-alpha-hydroxyprogesterone caproate, for preterm birth prevention during pregnancy, regarding the rates of Group B Streptococcus (GBS) colonization at term. In this retrospective observational cohort study of 565 women, 173 received intravaginal progesterone and 392 17-alpha-hydroxyprogesterone caproate. Observations revealed a decreased prevalence of rectovaginal GBS colonization at term in correlation to intravaginal progesterone.