History and Objectives: Considering the high incidence of Streptococcus hemolytic type B and its complications and its role in early neonatal infection and easy transmission from mother to infant and lack of information, this study was performed to determine its prevalence in pregnant women and its relationship with infection in referrals of Shabihkhani obstetric clinic in Kashan in 2000.

Materials and Methods: The descriptive and analytical strategy of this study was performed on 400 pregnant women with a gestational period equal to or greater than 35 weeks. For evaluation, a special questionnaire was designed in which information on age, occupation, nationality, level of knowledge, living area, multiparous status, abortions, history of preterm labor and diabetes and background illness were recorded. Sampling was made from vagina by a swab and they were transferred to related culture medium. The bacteria were diagnosed on the basis of biochemical tests and for statistical analysis chi-square and Fischer tests were used.

Results: Out of 400 evaluated cases, 32 cases (5.8%) with Streptococcus hemolytic type B were isolated and out of 23 infants born from mothers with positive colonization, only 2 cases (8.7%) has sepsis due to streptococcus hemolytic type B (P<0.003). In addition, none of the pregnant women with positive vaginal colonization for streptococcus showed any infection after labor. Meanwhile, other factors including background illnesses, diabetes, abortions, labor procedure, nationality, occupation, level of knowledge and living area did not have any role in this respect.

Conclusion: Since the incidence of this kind of infection is low in Iran, it is recommended to perform more studies in this field to determine the causative factors and to design health-training programs for pregnant women and to perform antibiotic prophylactic procedures in mothers with positive colonization to reduce subsequent complications.