Patient education: Group B strep screening (The Basics)

What is group B strep? — Group B strep, or "GBS," is short for "group B streptococcus." It is a type of bacteria that can cause infection.

Many people have GBS in some part of their body. It is often in the urinary tract, vagina, or rectum. Most of the time, it doesn't make the person sick. But sometimes, when a person is pregnant, GBS can cause an infection during birth. This can be serious for the pregnant person or their baby.

What is GBS screening? — Screening is a way to check for GBS when a person is pregnant and has no symptoms of infection.

What happens during GBS screening? — Your doctor or midwife will take samples, or "swabs," from your vagina and rectum. This is done between 36 and 38 weeks of pregnancy. It usually happens during a regular check-up. The test is very quick and doesn't hurt.

Your doctor or midwife will send the sample to a lab to check whether any GBS bacteria grow over time. This is called doing a "culture."

Most doctors and midwives also do a "urine culture" early in pregnancy. They will tell you exactly how to give a urine sample for this. The culture will show if there are any bacteria in the urine, including GBS.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

Your result can be:

●Negative – This means that GBS was not found in the samples.

●Positive – This means that GBS was found in the samples.

If your urine, vaginal, or rectal culture is positive for GBS, you will get IV antibiotics during labor. (An IV is a thin tube that goes into a vein.) This lowers the chances of passing the bacteria on to your baby during labor and birth. GBS infection can be serious in newborns.

More on this topic

Patient education: Group B strep and pregnancy (The Basics)
Patient education: Avoiding infections in pregnancy (The Basics)
Patient education: Prenatal care (The Basics)
Patient education: Urine culture (The Basics)

Patient education: Group B streptococcus and pregnancy (Beyond the Basics)
Patient education: Avoiding infections in pregnancy (Beyond the Basics)