35 Week Testing for Group B Streptococcus
What is Group B Streptococcus?
Group B Streptococcus (or GBS) is a bacteria that can live in the digestive, urinary and reproductive tract. In women, this bacteria can live in the vagina and rectum. It is not a sexually transmitted disease. Usually women who have GBS do not have any infections from it, and do not need treatment. Between 10-30% of pregnant women have GBS in the vaginal area. (This is not unusual, as women have many bacteria that live in the vaginal area.
Why am I tested for this at 35 weeks?
If a pregnant mother has GBS in the vaginal area, when their baby is born, it may be exposed to the bacteria. Under certain circumstances, the baby could become very ill. There are two types of infection: early onset GBS, that occurs within 1 week of life and late onset GBS, after 1 week of life. Early onset infection is most often caused by exposure during delivery. There is approximately 1600 cases of early onset infection, resulting in 80 deaths per year. Late onset infections can be caused by exposure at delivery or by contact with other people after delivery. 5% of babies with early or late infection may die.
How am I tested?
At around 35 weeks, your doctor will place a swab in the vagina and rectal area. This swab will be sent to the lab, and a culture for the bacteria will be done. The results usually take about a week to be reported. If positive, you will need treatment during labor in order to prevent exposure of baby.
I am GBS positive, so how am I treated?
If you test positive for GBS, you will need antibiotics during labor. These are given by an IV in your arm. If treated before delivery, the bacteria may re-grow. By treatment during labor, baby has the best chance of not being exposed. Although GBS is common during pregnancy, with appropriate treatment, infection of babies is rare.