Types of screening cultures
Perinatal Group B Streptococcal Disease comes from an intrauterine infection of the fetus from the spread of Group B Streptococcus from the vagina of a colonized woman who is typically asymptomatic. Medical studies show that prenatal screening cultures reduce the incidence of Perinatal Group B Streptococcal Disease. Studies of single institutions or health maintenance organizations show institutions with a culture-based screening policy have close to 90% of delivering women with documented GBS screening, and close to 90% of GBS-positive women received intrapartum antibiotics.  Cost-effectiveness analyses of the screening- and risk-based strategies have indicated that although the initial costs associated with specimen collection and processing make the screening strategy more expensive than the risk-based approach, the overall cost savings due to disease prevention do not differ importantly between strategies. 
- ^ Hafner E, Sterniste W, Rosen A, et al. Group B streptococci during pregnancy: a comparison of two screening and treatment protocols. Am J Obstet Gynecol 1998; 179:677--81.
- ^ Antimicrobial prevention of early-onset group B streptococcal sepsis: estimates of risk reduction based on a critical literature review Benitz WE, Gould JB, Druzin ML. Pediatrics 1999;103:e78.
- Prevention of Perinatal Group B Streptococcal Disease Revised Guidelines from CDC Morbidity and Mortality Weekly Report August 16, 2002. 51(RR11);1-22.