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Group B Strep: What It Is, How It's Treated & Why Testing Keeps Baby Safe
Updated on
September 5, 2024

Group B Strep: What It Is, How It's Treated & Why Testing Keeps Baby Safe

Feeling nervous about your Group B Strep test and not sure what it’s all about? We're here to help demystify it for you.

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Group B Strep: What It Is, How It's Treated & Why Testing Keeps Baby Safe.
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When you're pregnant, there are a whole host of health conditions you hear about for the first time, like group B Strep. This one comes up around 36-38 weeks when you'll likely be tested for the group B strep bacteria. In case you're wondering what all this means, we can get you up to speed.

What is group B strep?

“Group B Streptococcus (GBS) is a type of bacteria that can be found in the intestines and lower genital tract,” says Dr. Christy Evans, board-certified ob-gyn at Almond, a full-service, holistic practice based in Los Angeles. It's also very common—about one in four pregnant people carry the bacteria.

In general, most healthy adults don't need to worry about GBS—it comes and goes on its own and is usually harmless. Most people won't even know they have GBS unless it finds its way into their bladder and causes a urinary tract infection or UTI. "If [someone develops] a GBS infection in their bladder, they’ll probably feel an urgency to urinate, burning while urinating or possibly aching around the pubic bone,” says Evaly Long, a licensed midwife with Hummingbird Midwifery

UTIs caused by group B strep are easily treated with a course of oral antibiotics—though you’ll likely be treated again with an IV during labor due to the risk of recurrence.

Unlike the flu (or even the common cold), a group B strep infection isn't something you can catch by being around another person who has it—with one exception. “GBS can be passed back and forth between sexual partners,” says Long. And while it's possible to pass it to someone during sex, it's not considered a sexually transmitted infection. 

So why is GBS a potential concern? “Although many people carry GBS in their bodies without any issues, when it passes to a baby during birth, it can cause infections such as pneumonia, meningitis, or sepsis,” says Dr. Evans. This is why routine testing during pregnancy is important. 

What is the group B strep test?

Here's some good news: the group B strep test is a routine test that’s quick, easy and painless. It’s performed between 36 and 38 weeks of pregnancy. Your healthcare provider will take a quick swab of your vagina and rectum during one of your regular prenatal appointments. They’ll send the sample off to a lab, and results are usually available within a few days. 

In the case of an early or unexpected delivery (before you’re able to be tested) it's also possible to do several quick screening tests while you're in labor.

What are the symptoms of group B strep?

Most people who test positive for GBS won't show any symptoms. The positive test simply indicates that you're a carrier (meaning the bacteria is present in your body), but it doesn’t mean you'll necessarily pass it along to your baby. 

There are some symptoms that might put you at a higher risk of delivering a baby with group B strep if you’re positive at the time of delivery. These include:

  • A UTI that is a result of GBS during pregnancy

  • Preterm labor (prior to 37 weeks) and/or your water breaking

  • Water breaking 18 hours or more before delivery

  • Fever during labor (100.4 F or higher)

  • An infection of placental tissues and amniotic fluid

  • A previous baby with GBS 

You're also at an increased risk for group B strep if you have a medical condition that affects your immune system (such as diabetes, HIV, liver disease or cancer).

If you’re a carrier for GBS while in labor and you're not treated, there’s a 1-2% chance that your baby will get the infection. If you have the above risk factors/symptoms, the chance of infection in your baby is slightly higher.

What is the treatment for group B strep? 

More good news here—whether you test positive for GBS during that routine test around 36-38 weeks or if you’re screened in the hospital once you’re in labor, the treatment for group B strep during delivery is simple and very effective. Dr. Evans says it’s easily managed once you check in to the hospital: ”You'll receive intravenous antibiotics during labor—usually penicillin or ampicillin—[which help] to reduce the risk of passing the bacteria to your baby.”

It's recommended that the antibiotics are given at least 4 hours before delivery so they have time to begin working, after which Dr. Evans says additional doses will be given at regular intervals until your baby is born. There’s a risk of baby coming into contact with group B strep as they move through the vaginal canal (where the bacteria hangs out). If you're carrying group B strep and you're having a scheduled c-section birth, Dr. Evans says you’ll likely receive a round of “broad-spectrum antibiotics that cover GBS.”  It’s still a good idea to discuss your treatment plan with your doctor just to be sure.

And what about any future pregnancies? “It’s possible [to test positive again], but not guaranteed. GBS status can change between pregnancies,” Dr. Evans says. This is also why routine testing during each pregnancy is important.

How does group B strep affect your baby?

Before you find yourself stressing about this, here is more good news: with proper treatment, the chances of protecting your baby from group B strep are really high.

According to the American College of Obstetricians and Gynecologists, if antibiotics aren't given during labor, one or two out of every 100 babies might get sick. However, the risk is much lower when the birthing parent receives treatment. There are two kinds of GBS in babies: early-onset and late-onset, each with different symptoms.

Early-onset signs of a GBS infection in newborns appear shortly after birth and include rapid breathing (more than 60 breaths per minute), continuous grunting, or flaring of the nostrils. 

Babies with late-onset GBS infections begin showing symptoms anywhere from seven days to three months after birth. These signs include coughing and congestion, trouble eating, fever, drowsiness and seizures in severe cases. 

Prompt treatment can significantly improve outcomes. “If a newborn exhibits any of these symptoms, it's crucial to seek medical attention immediately,” says Dr. Evans. 

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