The GBS test is performed late in pregnancy, and it is usually recommended that cultures be taken from the lower part of the vagina and also from the rectum five weeks before delivery. The cultures are taken and compared to see if there is a streptococcal infection. During pregnancy, streptococcal infections have a greater impact on the baby because about 50% of pregnant women with streptococcal infections pass through the birth canal to the newborn during delivery, resulting in serious infection or even death of the baby. Therefore, for pregnant women with streptococcal infections, antibiotics are needed to prevent infection during labor and delivery, as well as increased protection during labor. For some pregnant women with high-risk factors, GBS screening can be done a little earlier, such as those at risk of preterm delivery, and those with suspected infection and fever.