[A study of group B streptococcus in pregnant women of eastern São Paulo].

A retrospective, cross-sectional study of 30 women seen at a Basic Health Care Unit (BHCU) in the Eastern Section of São Paulo, using interviews and medical record reviews, to determine how group B streptococcus (GBS) was detected in pregnant women. The patients in the studied sample received prenatal care at the UBS and delivered their babies between January 2009 and December 2010. Twenty-three of the women (76.7% of the total) underwent a GBS culture, 82.6% of which yielded a negative result and 17.4% of which yielded a positive result; 43.5% of these women underwent the test between 35 and 37 weeks of gestation; and 23.5% of the participants were not tested, mostly because no test was requested. GBS screening failures were shown have occurred during the selected period.