Maternal-Neonatal Outcome with Staphylococcus aureus Rectovaginal Colonization

OBJECTIVE: To estimate prevalence of rectovaginal colonization by Staphylococcus aureus among pregnant women with group B streptococcus (GBS) screening results and its association with maternal and infant outcomes. STUDY DESIGN: Cultures that detected both group 3 streptococcus (GBS) and S. aureus were obtained at 35 weeks of gestation. Computerized database search and chart review determined invasive neonatal infection and maternal outcomes at the time of delivery through 6 months postpartum. RESULTS: A total of 6,6.26 GBS screening cultures met study criteria, and 769 (11.6%) GBS isolates and 67 (1.0%) S. aureus were identified. No maternal S. aureus related outcomes were found. The rate of maternal methicillin-resistant S. aureus colonization was 0.1% (7 in 6,626). GBS-positive patients were twice as likely to be colonized with methicillin-susceptible S. aureus than GBS-negative patients. GBS-positive culture rates differed significantly by primary language: Spanish 10.0%, English 13.7%, Russian 26.9%, Cantonese 13.2%, Mandarin 11.5%, Arabic 15.9%, and other 17.8%. CONCLUSION: In our population, S. aureus colonization percentage (1.0%) was lower than the 7.5-8.2% reported by other medical centers, as was overall GBS carriage rate. S. aureus did not predispose to maternal or infant morbidity or mortality up to 6 months postpartum. (J Reprod Med 2011;56: 421-424)