Pregnancy: a magical time filled with glowing skin, bizarre cravings, and—oh yes—a whole host of tests. One of the less glamorous but very important tests is the GBS test. Never heard of it? Let’s dive into this fascinating bacterial tale with just the right mix of science and sass.
What Does GBS Stand For?
GBS stands for Group B Streptococcus, which is one of the many types of bacteria that naturally live in your body. Think of it as a roommate in your digestive tract or lower reproductive area. Most of the time, it’s a silent tenant, causing no issues. But in pregnancy, it’s the one you have to keep an eye on—kind of like that roommate who always “forgets” to clean the kitchen.
What Is GBS, Really?
GBS is just one of the many bacteria that can be found in the human body, and its presence doesn’t mean you’re sick or unclean. About 1 in 3-4 women carry GBS, often without symptoms. It’s one of those sneaky bacteria that are part of the natural microbiome but can act out of line under certain circumstances—like during childbirth.
When and Why Is It Tested For?
Around 36 to 37 weeks of pregnancy, your healthcare provider will test for GBS. Why then? Because the closer we are to your due date, the more accurate the test will be for identifying if GBS is hanging around.
If GBS is present during labor, there’s a chance it could be passed to your baby, which can lead to serious infections like:
- Sepsis (a blood infection)
- Pneumonia ( a lung infection)
- Meningitis (an infection of the brain and spinal cord)
The test is a preventive step to keep your little one safe and sound. The risk is higher if the baby is born early, before 37 weeks.
How Is the Test Done?
Good news: the GBS test is quick and painless. Your provider will take a simple swab of your vaginal (lower one third) and rectal areas. Yes, it sounds awkward, but it’s over in seconds—and it’s all for a good cause!
What If GBS Is Found in Urine?
Sometimes GBS shows up in a routine urine test during pregnancy. If this happens, it means there’s a higher concentration of GBS in your body, and you’ll need antibiotics during labor to reduce the risk of passing it to your baby. Bonus: treating GBS in urine during pregnancy can also help prevent urinary tract infections (UTIs). If you have GBS in your urine at any pint in pregnancy, you do not need the swab at 36/37 weeks. You will be treated as GBS positive.
What Happens If You Test Positive?
Testing positive for GBS is not a reflection of your hygiene or health. It just means you’ll need antibiotics during labor. These antibiotics are given through an IV and work to prevent the bacteria from reaching your baby.
- No need to stress—this treatment is highly effective at protecting newborns.
- You won’t need antibiotics before labor because GBS can return even after treatment. (Spoiler alert: GBS can’t be eradicated permanently.)
Can GBS Be Treated During Pregnancy?
Here’s the deal: even if we treat GBS with antibiotics earlier in pregnancy, the bacteria can come back. It’s like a boomerang—you throw it away, and it finds its way back to you. That’s why we focus on treating it during labor, when it’s most important for your baby’s protection.
Fun (and Witty) Facts About GBS
- You Can’t Get Rid of It: GBS is a natural part of the human microbiome, so there’s no way to permanently eliminate it. It’s a matter of managing it when it matters most.
- You’re Not Alone: About 25% of pregnant women are GBS-positive. It’s common and manageable.
- Babies Are Resilient: Thanks to modern medicine, even if you test positive, the risk of GBS-related complications is very low when antibiotics are used.
- It’s Not an STI: GBS isn’t sexually transmitted, so there’s no need for side-eyes or awkward conversations.
- Group B Streptococcus (GBS) is a transient bacterium, meaning you can carry it sometimes, but it’s not necessarily present all the time. This is why the GBS test is performed around 36 to 37 weeks of pregnancy—to provide the most accurate picture of whether GBS is currently present. Testing too early might miss it if it develops later, while testing too late could delay the necessary steps for protecting your baby during delivery. This timing ensures your healthcare team can act effectively if needed.
How Is GBS Treated?
Treatment for Group B Streptococcus (GBS) depends on the situation: whether it’s detected in the urine during pregnancy or for delivery purposes to protect the baby.
1. GBS in Urine During Pregnancy
- Why It’s Treated: If GBS is found in your urine, it indicates a higher bacterial load, increasing the risk of urinary tract infections (UTIs), which can cause kidney infections and complications for you and your baby.
- Treatment: Oral antibiotics (e.g., amoxicillin or cephalexin) are prescribed to clear the infection and prevent UTIs.
- Threshold for Treatment: GBS in the urine is typically treated if levels are ≥100,000 CFU/mL (colony-forming units per milliliter). Lower levels might not require treatment unless symptoms are present, but the detection still indicates the need for antibiotics during labor.
- Implication for Delivery: If GBS is found in your urine, you’ll automatically be treated as GBS-positive during labor, the late-pregnancy GBS test does not need to be done.
2. GBS Treatment for Delivery
- Purpose: To prevent GBS transmission to the baby during labor and delivery, as GBS can cause serious infections like sepsis, pneumonia, and meningitis in newborns.
- Treatment: Antibiotics are given intravenously (IV) during labor. The most commonly used antibiotics are:
- Penicillin (first choice)
- Ampicillin (alternative)
- For penicillin-allergic individuals: alternatives like clindamycin may be used if the GBS strain is sensitive, or vancomycin if sensitivity testing doesn’t allow clindamycin use.
- Timing: Antibiotics are administered every 4 hours during labor until delivery. Ideally, treatment should begin at least 4 hours before birth to ensure effectiveness.
Why Treatment Timing Matters
GBS is not treated earlier in pregnancy (unless detected in urine or causing a UTI) because the bacteria can return even after antibiotics. Administering antibiotics during labor is the most effective way to protect the baby at the critical time of exposure.
By treating GBS appropriately during pregnancy and delivery, the risk of complications for the baby is drastically reduced. Always discuss your specific situation with your healthcare provider for the best care plan!
Timing of Antibiotics for GBS: Does It Matter When Your Water Breaks or If You’re Ready to Deliver?
When it comes to preventing GBS transmission during labor, timing is everything. Administering antibiotics at least 4 hours before delivery is ideal to allow sufficient time for the medication to build up in your bloodstream and provide protection to your baby. However, labor isn’t always predictable, and situations like your water breaking early or arriving ready to deliver can complicate the timing.
What If Your Water Breaks?
If your water breaks—whether before labor begins (premature rupture of membranes) or during active labor—it’s an important factor in GBS management:
- Water Breaking Before Labor (PROM):
- If your water breaks before labor begins (pre-labor rupture of membranes or PROM), the clock starts ticking. The longer the time between water breaking and delivery, the greater the risk of GBS transmission to your baby.
- Antibiotics are typically started as soon as possible after you arrive at the hospital, even if active labor hasn’t started, to reduce the risk of infection.
- In some cases, labor may be induced to minimize prolonged exposure.
- Water Breaking During Labor:
- If your water breaks during labor and antibiotics haven’t been started yet, your healthcare provider will begin treatment immediately. The goal is still to administer at least one dose (ideally 4 hours before birth), but even partial coverage is better than none.
What If You Arrive Ready to Deliver?
Labor can move quickly, and sometimes there’s little time to administer antibiotics. If you arrive at the hospital in active labor and close to delivery:
- Antibiotics Are Still Given: Even if there’s less than 4 hours before delivery, healthcare providers will administer antibiotics immediately. While it’s not as effective as the ideal 4-hour window, any antibiotic exposure reduces the risk of GBS transmission.
- Baby Will Be Monitored Closely: If there wasn’t enough time for adequate antibiotic coverage, your baby may require additional monitoring after birth. This includes:
- Observing for signs of infection (e.g., fever, difficulty breathing).
- Blood tests or a complete blood count (CBC) if needed.
What If You Decline or Don’t Receive Antibiotics?
- If antibiotics aren’t administered, your baby will likely receive more intensive monitoring for signs of infection.
- In some cases, the baby may receive antibiotics as a precaution.
The Takeaway
Timing matters, but labor and delivery are often unpredictable. The best approach is to inform your healthcare team as soon as you arrive, so they can start antibiotics as quickly as possible. Whether your water breaks early or you’re ready to deliver, there are protocols in place to minimize risks and keep your baby safe. Let your provider know about any GBS-related concerns ahead of time, so they can plan accordingly.
The GBS test may not be the most glamorous part of pregnancy, but it’s one of the most important. By testing for this sneaky bacteria and taking simple preventive measures, your healthcare team ensures a smooth delivery and a healthy start for your baby. So, embrace the swab, trust the process, and remember: you’ve got this!