Tehran University of Medical Sciences Journal of Family and Reproductive Health 1735-8949 2 3 2008 09 15 139 141 Farzaneh Broomand Department of Obstetrics and Gynecology, Urmia University of Medical Sciences, Urmia, Iran Fariba Abbasy Department of Pathobiology, Urmia University of Medical Sciences, Urmia, Iran Rahim Nejad Rahim Department of Infectious Disease, Urmia University of Medical Sciences, Urmia, Iran Zahra Yekta Department of Community Medicine, Urmia University of Medical Sciences, Urmia, Iran Fariba Nanbaksh Department of Obstetrics and Gynecology, Urmia University of Medical Sciences, Urmia, Iran Golpira Mirfakhraie Department of Obstetrics and Gynecology, Urmia University of Medical Sciences, Urmia, Iran 2015 10 04 Objective: Preterm premature rupture of membranes (PPROM) occurs in 2% of all pregnancies. The aim of this study was to compare positive cultures of GBS in two groups of pregnant women. Materials and methods: This case control research was conducted on 242 pregnant women: first group was consisted of 117 pregnant with PPROM and gestational ages between 26-37 weeks; second group was consisted of 125 term pregnant women with intact membranes and before onset of labor. Rectovaginal and urine samples were studied using specific culture medium of GBS, "Todd Hewitt Broth". The percentage of positive results was calculated using odds ratio and chi-square test. Results: GBS cultures were positive in 20 cases (17%) in PPROM group and 5 cases in group of term pregnant (4%) (Odds ratio=4.95 CI= 1.79-13.67, p=0.001). Past history of preterm labor and neonate hospitalization were more common in PPROM group but without any significant relationship to positive cultures. Conclusion: Our study showed significant difference of GBS colonization rate between two groups (p=0.001). According to CDC and ACOG guidelines routine screening and treatment of positive cases are indicated. https://jfrh.tums.ac.ir/index.php/jfrh/article/view/47 https://jfrh.tums.ac.ir/index.php/jfrh/article/download/47/47