Streptococcus b test is mainly used to detect whether the fetus has intrauterine infection and whether the pregnant woman has chorioamnionitis and high-risk pregnancy. 1. Intrauterine infection: after pregnant women are infected with Streptococcus b, it is easy to induce fever, dysuria, dyspareunia and uterine tenderness, and even lead to neonatal injury, induce fetal infection, preterm labor, sepsis and neonatal meningitis and other symptoms. 2. Chorioamnionitis: the presence of b-group streptococcus often has a great impact on the newborn, so pregnant women need to undergo b-group streptococcus screening for chorioamnionitis in late pregnancy. 3. High-risk pregnancy: b streptococcus may cause abnormal development of the fetal nervous system, inducing hydrocephalus or mental retardation, and when the condition is more serious, the pregnancy needs to be terminated. It is recommended that pregnant women actively cooperate with the relevant examinations in late pregnancy, abnormalities, and actively receive treatment.