Rapid Detection of Group B Strep- 35-37 Week Study

The purpose of this study is to determine whether a rapid bedside diagnosis of Group B Strep growing in the vagina and rectum can be performed with similar success to the routine culture.

Early Onset Group B Strep (GBS) neonatal infections is one of the leading infections in newborns, nearly all of which are acquired by vertical transmission at the time of childbirth. Most cases can be prevented by identifying women who are colonized with GBS in the vaginal-rectal area and giving these colonized women prophylactic antibiotics in labor. About 15 -20% of women are colonized and nearly all of these women are asymptomatic. Because it takes up to 48 hours to obtain culture results, it is currently recommended to perform cultures in the clinic about 3 - 5 weeks prior to their due date and then prophylaxing those women colonized with GBS with antibiotics when they come in to labor. There are several downsides to this strategy. All women who present with preterm labor are treated until culture results become available (overtreatment), women who go into labor while waiting for culture results are all treated (overtreatment), prior studies have shown 33% of women are positive at 35 weeks, but negative at birth (overtreatment) and 10% are negative at 35 weeks and positive at birth (undertreatment), lost or missing culture results (over- or undertreatment). Using microfluidics and fluorescent PCR, a new test can identify GBS reliably in 30 to 45 minutes in vitro. This study proposes to evaluate the clinical performance (sensitivity, specificity, positive and negative predictive value) of the microfluidic rapid GBS technique in selected women presenting at 35 - 37 weeks to antenatal clinics at the University of Michigan compared to standard culture.