Florindo, CDamião, VLima, JNogueira, IRocha, ICaetano, PRibeiro, LViegas, SGomes, JPBorrego, MJ2014-06-102014-06-102014J Matern Fetal Neonatal Med. 2014;27(6):640-2.http://hdl.handle.net/10400.26/6472OBJECTIVE: To evaluate the positive predictive value (PPV) of group B Streptococcus (GBS) cultures at 35-37 weeks of gestation relative to GBS colonization status at delivery. METHODS: Rectovaginal swabs from 221 women at labor in four Lisbon hospitals were collected for GBS screening according to the CDC guidelines. RESULTS: The PPV was 24.4%. IAP was administered to 100% of prenatally GBS positive women. There was no case of early onset GBS disease (EOD). CONCLUSIONS: Poor accuracy of prenatal cultures in identifying true candidates for IAP highlights the need for Portuguese clinical and laboratory guidelines to prevent EOD and antibiotic overtreatment of pregnant women.engPregnancy Complications, InfectiousStreptococcal InfectionsInfectious Disease Transmission, VerticalInfecções por EstafilocócosComplicações Infecciosas na GravidezTransmissão Vertical de Doença Infecciosajournal article10.3109/14767058.2013.820700