Pregnancy Weeks 35-36 – Group B Strep Test

Group B Strep Test is performed between Week 34 and 35, to determine if the women has the Group B Strep Bacteria.

The test involves a swab of both the vagina and the rectum. The sample is then taken to a lab where a culture is analyzed for any presence of GBS. Test results are usually available within 24 to 48 hours.

If you test positive for GBS this simply means that you are a carrier. Not every baby who is born to a mother who tests positive for GBS will become ill. Approximately one out of every 200 babies whose mothers carry GBS and are not treated with antibiotics, will develop signs and symptoms of GBS disease.

In this case your physician will want to use antibiotics for prevention and protection.

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.

Those women who test positive for GBS are said to be colonized. A mother can pass GBS to her baby during delivery. GBS is responsible for affecting about 1 in every 2,000 babies in the United States. Not every baby who is born to a mother who tests positive for GBS will become ill.

Although GBS is rare in pregnant women, the outcome can be severe, and therefore physicians include testing as a routine part of prenatal care.