Strep B Test Test
A group B strep (GBS) test checks for GBS bacteria in your body. If you are pregnant, the test helps prevent passing the bacteria to your baby during birth.
What this test measures
The test checks for group B streptococcus (GBS) bacteria, which are commonly found in the digestive tract, urinary tract, and genital area.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
If you are pregnant and test positive for GBS, you will be given antibiotics intravenously during labor to prevent passing the bacteria to your baby.
Frequently asked questions
What is group B strep (GBS)?
GBS is a type of bacteria commonly found in the digestive tract, urinary tract, and genital area. Many healthy people have it without symptoms.
Why is GBS testing done during pregnancy?
Testing is done to find GBS bacteria so that antibiotics can be given during labor to prevent passing the infection to the baby.
What happens if I test positive for GBS?
You will receive antibiotics intravenously during labor, at least four hours before delivery, to protect your baby.
Can GBS cause problems in newborns?
Yes, GBS can cause serious infections in newborns, including bloodstream infections, pneumonia, and meningitis.
Do I need antibiotics if I have a planned C-section?
You may not need antibiotics, but you should still be tested because you could go into labor before your scheduled C-section.
Related lab tests
Sources
- MedlinePlus: Strep B Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.