here is a bunch of works cited info with studies that will have hard numbers--it is going to be an obnoxious list though...sorry...but for those really interested in studies and such there is a lot of great info here.
Also, I forgot to mention that in the research I did the numbers in Schrag's study said that of the babies who got GBS from mama 75% of those mamas had received IV abx per protocol...so...there is that, too. Following The protocol for abx doesn't=zero chance of infection.
Every family determines what is right for them, but no mama should be forced to take abx against her wishes just because care providers are following protocol and can't give specific info on real risks vs. scare tactics.
J. Stoll, MDa, Nellie I. Hansen, MPHb, Pablo J. Sanchez, MDc, Roger G. Faix, MDd, Brenda B. Poindexter, MD, MSe, Krisa P. Van Meurs, MDf, Matthew J. Bizzarro, MDg, Ronald N. Goldberg, MDh, Ivan D. Frantz III, MDi, Ellen C. Hale, RN, BS, CCRCj, (2011). Early Onset Neonatal Sepsis: The Burden of Group B Streptococcal and E. coli Disease Continues. Pediatrics, 128, 390. (Stoll, et al., 2011)
CDC - 2010 Guidelines for Prevention of Perinatal GBS - Group B Strep. (n.d.). Centers for Disease Control and Prevention. Retrieved February 20, 2012, from http://www.cdc.gov/groupbstrep/guidelines/guidelines.html (CDC, 2012)
R. Phares, PhD; Ruth Lynfield, MD; Monica M. Farley, MD; Janet Mohle-Boetani, MD; Lee H. Harrison, MD; Susan Petit, MPH; Allen S. Craig, MD; William Schaffner, MD; Shelley M. Zansky, PhD; Ken Gershman, MD; Karen R. Stefonek, MPH; Bernadette A. A. (2008). Epidemiology of Invasive Group B Streptococcal Disease in the United States, 1999-2005. JAMA, 299(17), 2056-2065. (Phares, et al., 2008)
W. David MD; Schuchat, Anne MD; Gibbs, Ronald MD; Sweet, Richard MD; Mead, Philip MD; Larsen, John W. MD. (2000). Prevention of Perinatal Group B Streptococcal Infection: Current Controversies. Obstetrics and Gynecology, 96(1), 141-145. (David, et al., 2000)
K. Van Dyke, Ph.D., Christina R. Phares, Ph.D., Ruth Lynfield, M.D., Ann R. Thomas, M.D., Kathryn E. Arnold, M.D., Allen S. Craig, M.D., Janet Mohle-Boetani, M.D., Ken Gershman, M.D., William Schaffner, M.D., Susan Petit, M.P.H., Shelley M. Zansky. (2009). Evaluation of Universal Antenatal Screening for Group B Streptococcus. The New England Journal of Medicine, 360, 2626-2636. (Van Dyke,et al., 2009)
J. Schrag, D.Phil., Sara Zywicki, M.P.H., Monica M. Farley, M.D., Arthur L. Reingold, M.D., Lee H. Harrison, M.D., Lewis B. Lefkowitz, M.D., James L. Hadler, M.D., Richard Danila, M.D., Paul R. Cieslak, M.D., and Anne Schuchat, M.D., .. S. (2000). Group B Streptococcal Disease in the Era of Intrapartum Antibiotic Prophylaxis. The New England Journal of Medicine, 342, 15-20. (Schrag, et al., 2000)
A. Joseph, MD; Suma P. Pyati, MD; N. Jacobs, MD. (1998). Neonatal early-onset Escherichia coli disease the effect of intrapartum Ampicillin. Archives of Pediatrics & Adolescent Medicine, 152, 35-40. (Joseph, et al., 1998)
F. Snail (2003). Intrapartum antibiotics for group B streptococcal colonisation (Cochrane
review). The Cochrane Library, 4, 1. (Snail, 2003)
Gilbert, GA. (2002). Preventing perinatal group B streptococcal infection: the jury is still out
(editorial). Medical Journal of Australia, 178, 199-200 (Gilbert, 2002)