Community Question: GBS Testing

It's our first installment of "Sincerely, Your Doula"!  We're here to answer a question submitted by our community that will hopefully be helpful to you, as well!

"I'm 34 weeks pregnant today.  My doctor said that at my next appointment I'll be tested for 'GBS'.  What is that?  How do they test for it? What if I test positive?"  -Jessica (Princess Anne, MD)

Thank you for your question, Jessica!  Every pregnant woman in the United States who is being seen by a medical care provider will be offered the GBS screening around the 36th week of pregnancy.  You may want to know what GBS is and what it means if you're tested positive for it.

GBS (Group B Streptococcus) is a colonization of bacteria living in the gut of many healthy people.  In pregnancy, it is possible that what was once a "normal" colonization, may become an over-colonization, spreading to the vagina.  The risk is when baby is born vaginally, and may pass through the bacteria, becoming colonized as well, and subsequently ill.

So, at or around your 36th week of pregnancy, your care provider will likely request a swab (Q-tip) of your vaginal tract (and possibly rectum as well) for a culture test to determine if GBS has colonized there.  If your culture comes back positive (as it does for up to 30% of pregnant women!), then your care provider will likely recommend intravenous antibiotics during your labor process to act as a prevention against illness for your baby.  

GBS colonization in your vaginal tract is NOT harmful to you and the risk of your baby becoming ill is very small.  So, as I often share with my clients: GBS is something to be aware of, not something that you should lose sleep over.

Of course, in our childbirth education class, we always suggest asking questions and learning as much about your pregnancy and body as you want/need.  There are many layers to every test, routine procedure, and treatment, and we encourage you to do your research, ask your doula for more resources, and talk with your care provider about all of your concerns and options.  Here are some of the most common questions we get from our childbirth education class and doula clients concerning GBS (click on these links for statistics if you're a research gal like me):

  1. What is the risk of my baby becoming infected with GBS?
  2. If my baby is infected, what are the chances that they will become ill?
  3. Are there risks to antibiotic use in labor for me or my baby?
  4. Do I have to be tested?
  5. Can I prevent GBS colonization in my vaginal tract?
  6. How accurate is the test?
  7. How effective is the antibiotic treatment?

What are some other questions about GBS that you have or have had?

If you have a question that you want our doulas to answer, please submit it here in the comments or email us at  We're happy to share our expertise about anything concerning pregnancy, birth, our services, parenting, feeding, etc!