I just went for my appointment and my gynea did a Group B Strep test. What is the purpose of this test?

Group B streptococcus (GBS) is a type of bacterial infection that can be found in a pregnant woman’s vagina or rectum. This bacteria is normally found in the vagina and/or rectum of about 25% of all healthy, adult women. Women who test positive for GBS are said to be colonized. A mother can pass GBS to her baby during delivery. http://americanpregnancy.org/pregnancy-complications/group-b-strep-infection/ I had strep B during my 1st pregnancy. There are 2 types of treatments, one is given antibiotics before delivery while another one is given IV drip with antibiotics during the labour. The antibiotics IV drip need at least 4 hours to take effect to protect the baby. However, for me due to my fast labour (3 hours), the IV drip did not manage to take effect. Thus, my newborn needed to be take antibiotics injection every 8 hours until the bacteria culture results was out and confirmed clear from infection.