Prenatal antibiotic treatment does not decrease group B streptococcus colonization at delivery.

Author(s): Baecher L, Grobman W

Affiliation(s): Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, IL, USA. lbaecher@hotmail.com

Publication date & source: 2008-05, Int J Gynaecol Obstet., 101(2):125-8. Epub 2007 Dec 20.

Publication type: Research Support, Non-U.S. Gov't

OBJECTIVE: To evaluate whether an outpatient antibiotic regimen decreased group B streptococcal (GBS) colonization to preclude the use of intrapartum antibiotics. METHODS: A double-blind randomized controlled trial evaluating prenatal oral amoxicillin versus placebo with the primary outcome of GBS colonization at the time of labor. RESULTS: Of those patients receiving both amoxicillin and a repeat culture at the time of labor, 6 of the 14 (43%) tested positive for GBS colonization. Given persistent GBS colonization of 67% (10/15) in the placebo group, treatment with amoxicillin did not significantly impact colonization at the time of delivery (P=0.20). CONCLUSION: A regimen of outpatient amoxicillin was associated with persistent GBS colonization in 43% of women at the time of labor. Oral prenatal antibiotic prophylaxis against GBS does not sufficiently reduce colonization to preclude intrapartum intravenous antibiotics.