Group B streptococcal testing during pregnancy: survey of postpartum women and audit of current prenatal screening practices

Abstract

Objective: Group B Streptococcus (GBS) can be transmitted from mother to child during delivery. At the time of the study, Nova Scotia guidelines for screening pregnant women for the presence of GBS recommended using one of two testing methods. The objective of this study was to determine the level of compliance with GBS testing recommendations and to determine women's knowledge of, attitudes towards, and beliefs about prenatal screening for this infection.

Methods: All women who gave birth at a single tertiary care unit during a seven-week period were approached to participate in the study. Study participants were interviewed using a questionnaire to determine their knowledge of, attitudes towards, and beliefs about prenatal screening. Medical and laboratory records were reviewed in order to audit the prenatal screening practices.

Results: A total of 24.5% of study participants were screened for the presence of GBS by culture of a vaginal-rectal swab taken at 35 37 weeks' gestation, and 75.5% were assessed using the risk factor approach. Of the women screened by culture, 19% were identified as needing antibiotic treatment compared with 25% of those screened by assessment of risk factors. Women were significantly less knowledgeable about GBS than about other specific infections, and they felt that the threat of GBS infection for their baby was lower than the threat of the other infections. However, many of these women were uncertain about the threat that GBS poses during pregnancy.

Conclusion: Screening for GBS by culture rather than by assessing risk factors would have reduced antibiotic usage in our study population by 23%. These results indicate that all women should be counselled regarding GBS infection and should be tested using the culture-based approach at 35 to 37 weeks' gestation.