Diagnostic yield of real-time polymerase chain reaction in the diagnosis of intrapartum maternal rectovaginal colonization by group B Streptococcus: a systematic review with meta-analysis.

Group B Streptococcus is the leading etiologic factor of neonatal sepsis. Intrapartum real-time polymerase chain reaction (RT-PCR) may allow faster and more accurate detection of maternal colonization. The aim of this study was to determine the sensitivity and specificity of RT-PCR when compared to the reference standard culture in selective broth media collected from rectovaginal tract from laboring women. We selected 15 studies that included 6368 women. Papers selection, data extraction, and quality assessment were carried out by two independent researchers. The prevalence of maternal colonization was 23.8% by RT-PCR and 22.1% by culture. The meta-analysis demonstrated an RT-PCR sensitivity of 93.7% (CI 92.1-95.3), and specificity of 97.6% (CI 97.0-98.1). This result is above the cutoff point defined by the Centers for Disease Control and Prevention for clinical usefulness. In conclusion, RT-PCR for GBS screening in labor ward is a promising tool; however, further well-designed studies to justify its use are needed.