Group B Streptococcus (GBS) is a parthenogenic anaerobic Gram-positive streptococcus that normally resides in the vagina and rectum, it is a conditionally pathogenic bacterium, and GBS infection is not generally pathogenic in normal healthy people. According to statistics, normal women carry the bacteria at a rate of about 30%, but in pregnant women about 10%-30% of them are infected with GBS, 40%-70% of which may be passed to the newborn during delivery. If a newborn carries the bacteria, about 1% to 3% will develop early invasive infection, causing sepsis, meningitis, pneumonia, etc. in newborns, of which 5% will lead to death, and even in newborns who survive the infection, there may be serious neurological sequelae, including hydrocephalus, mental retardation, microcephaly, deafness, etc. Also, group B streptococci can cause infection in pregnant women, cause preterm labor, fetal failure (low birth weight babies), premature rupture of membranes, and late miscarriage. In 1996, the Centers for Disease Control (CDC) and other agencies jointly developed the Guidelines for Screening and Prevention of Perinatal Group B Streptococcal Infections, which were revised in 2002 and 2010, and have largely reduced the incidence and risk of perinatal group B streptococcal infections, with the incidence rate decreasing from 1.7/1000 births in the early 1990s to 0.34- 0.37/1000 births in recent years. 0.37/1000 newborns. The prevention of GBS infection in the perinatal period in China is based on the GBS prevention guidelines issued by the CDC in 2010, which provides vaginal and rectal screening for GBS in pregnant women at 35-37 weeks of gestation, which can improve the efficiency of prevention, save resources, and at the same time can substantially reduce the use of unnecessary antibiotics. Of course GBS can also be used for the etiologic diagnosis of neonatal infections.