Labor & Birth, pregnancy testing

GBS & Why We Are Tested For It

GBS, or Group B Streptococcus, is not the same thing that causes a sore throat (which is Group A Streptococcus). It’s a bacteria that occurs naturally in the body, most often in the digestive or reproductive tracts. It’s so common that 1 in every 4 pregnant people are carriers of the bacteria! You probably don’t even know if you have it.

So how do I know if I have it?

Your medical provider will test for GBS around week 36 or 37 of pregnancy by taking a sterile swab and wiping it just inside the vagina, across the perineum, and around the anus. (Some providers encourage the birthing parent to swab themselves during their appointment.) The swab is sent to be cultured, and your provider will get the results in about 48 hours.

I tested positive. What now?!

While it’s super common (like I said, 1 in 4!), it can be scary to hear that diagnosis. While it’s generally not harmful to you or your baby while they’re still cookin’, the baby may be susceptible to early on-set GBS illness if left untreated. This could lead to meningitis, pneumonia, or sepsis. However, your baby’s chances of getting GBS illness go from 1 in 200 if untreated to 1 in 4,000 if you are treated before birth.

Your baby may be susceptible if left untreated

Okay, so what is the treatment?

Since colonizations of Group B Strep can come and go, there is no way to treat it before the birth process begins. Once you go into labor and arrive at your birthing place, your providers will likely treat you with antibiotics via IV drip every four hours. While it may sound like a drag to be hooked up to an IV pole throughout your labor, it generally takes 15-30 minutes for the antibiotic bag to empty into your body. At that point, the IV port can be saline- or hep-locked and detached.

Note: If you’ve tested positive for GBS, it is essential to note when your water breaks and to notify your provider. The more time between your water breaking and getting antibiotics, the higher the baby’s chances will contract GBS illness in the womb.

It generally takes 15-30 minutes for the antibiotics to be administered

Are there any other considerations I need to make?

Taking a probiotic can reduce the effects of the antibiotic’s impact on your baby’s microbiome. Other options, including probiotics, might lessen your chances of being colonized with GBS. However, research indicates that there isn’t much we can do to prevent the colonizations from forming. Speak with your provider to create a plan that you are both comfortable with. Ultimately, a positive diagnosis of Group B Strep shouldn’t drastically change the type of birth you are picturing for yourself.


Taylor Rush is a Certified Labor and Postpartum & Infant Care Doula, a Childbirth Educator, and Infant Feeding Specialist with Flora & Finn Birth Services. Contact us today to discuss how she can support you on your pregnancy, birth & parenting journey!

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