Prevalence of rectovaginal colonization by group B Streptococcus in pregnant women seen at prenatal care program of a health organization

OBJECTIVE: To evaluate the prevalence of group B Streptococci in pregnant women of a corporate health program, as well as the epidemiological correlations. METHODS: This retrospective study used medical records of patients who participated of the prenatal care program at a private hospital in the city of São Paulo (SP), Brazil, from 2015 to 2016. Those who abandoned the program or had incomplete data in their medical records were excluded. Quantitative variables were described by means, standard deviations, median, minimal and maximal values. Parity and socioeconomic status were described by absolute frequency and percentages. We used logistic regression models in the software (SPSS) to analyze correlations of variables according to vaginal-rectal culture, considering a 95%CI and p-values. Variables were age, number of pregnancies, weight gain in pregnancy and gestational age at delivery. RESULTS: A total of 347 medical records were included, and after applying the exclusion criteria, 287 medical records composed the final sample. Patients’ age ranged between 17 and 44 years. Mean age was 30.6 years, 67 patients had positive result for group B Streptococcus (prevalence of 23.3%; 95%CI: 18.7-28.5). CONCLUSION: Considering the high prevalence of group B Streptococcus in our service, the antibiotic prophylaxis strategy based on rectovaginal culture screening approach seems to be cost-effective.