Ep 260: Pregnancy & GBS (Group B Strep) – Updated!

Dr. Nicole (00:00): What is group B strep? What are the chances that you have it? Why does it even matter for your pregnancy? Should you be taking probiotics to try and reduce the risk? You'll get the answers to all of those questions and more in this episode of the podcast.

(00:23): Welcome to the All about Pregnancy and birth podcast. If you're having a baby in the hospital, you are giving birth in a system that too often takes away power from women over what happens in their own bodies. I'm Dr. Nicole Calloway Rankins, a practicing board certified OB GYN, who's had the privilege of helping well over a thousand babies into this world. I've been a doctor for over 20 years and I'm here to help you take back your power, advocate for yourself, and have the beautiful pregnancy and birth that you deserve. This podcast is for educational purposes only, and it's not a substitute for medical advice. Check out the full disclaimer at drnicolerankins.com/disclaimer. Now let's get to it. Hello there. Welcome to another episode of the podcast. This is episode number 260. Whether this is your first time listening or you've been here before, I am so glad you're spending some time with me today.

(01:17): In this episode, you are going to learn all about group B strep or GBS. It is one of the tests that is done during pregnancy, and I first did this episode in 2019, and periodically I go back and update older episodes as things change in a few things have changed about GBS testing since I did that episode. So you're going to get an update today. So in this episode, you're going to learn what exactly is GBS, what are your chances of having it? What are risk factors for having GBS? Why does it even matter? How does GBS affect a pregnancy? How does it affect your baby? How we test for it, how we treat it? Any long-term implications and should you try and clear it or get rid of it during pregnancy? So tons of useful information in this episode. Now, before I get into the episode, I want to do a quick listener shout out.

(02:10): This is to Jessica Levinson and the title of the review says Great Resource and the review says, I always look forward to the latest episodes. I wish I had found this podcast during my first pregnancy, but I'm grateful to have had it for my second and now third Babies. Dr. Rankins is easy to listen to. The information is trustworthy and helps me feel confident in my birth. Thank you. Thank you so much, Jessica, for leaving me that kind review and Apple Podcast. I so appreciate it and I'm grateful that I have been doing this long enough that folks have been with me long enough to have more than one baby. That is so, so special to me and I appreciate it. And having my resources available for more than one pregnancy is one of the things that people like about my childbirth class as well.

(03:00): The birth preparation course, you can buy it once and you have it for all your pregnancies because you get lifetime access. You can check out all the details of the birth preparation course, my signature online program that gets you calm, confident and empowered to have a beautiful birth with a focus in the hospital. Check out all the details, dr nicole rankins.com/enroll. Also, if you want to leave me and review an Apple podcast and potentially get a shout out on a future episode, please do so. I would love, love to hear from you. So let's get into GBS. So GBS stands for group B streptococcus or group beta streptococcus, and it's a type of bacterial infection caused by the bacteria streptococcus aacte. This bacteria is commonly found in the gastrointestinal tract and also in the genital urinary tract. So that's the reproductive system and the urinary system of healthy adults.

(03:58): And it is often present or most often present without causing any symptoms. Actually, however, GBS, and I'm just going to call it GBS or group B strep during the episode, GBS can be problematic in certain situations, particularly for newborns and individuals with weakened immune systems. Now, as far as how many women have GBS, it colonizes the gastrointestinal and genital tracts of anywhere from 15 to 40% of pregnant women. Okay? So that is a lot. The chances are fairly high that you are going to be a carrier of GBS and colonizes just means that the bacteria is present in your system and typically it means that it's asymptomatic, so you're not having any symptoms of it. It just means that the bacteria is there. Now, why does GBS colonization matter? So when a mom is colonized with GBS, this is the critical determinant of whether or not a baby gets infected with GBS within the first few days of life.

(05:05): That vertical transmission, that's what it's called, mother to child transmission, it's called vertical transmission, primarily occurs when GBS ascends from the vagina into the amniotic fluid after the onset of labor, particularly after the water is broken, the bag of water or the membranes are what protect the baby from bacteria that are in the vagina. And when that barrier is gone, then bacteria in the vagina can potentially go up and cause an infection around the baby. And GBS is one of the bacteria that can do that. I'll talk about at the end what are the things that happen when a baby is infected with GBS. Now, it can also occur with intact membranes, so your water hasn't broken yet. That risk is not very common though, and it can also happen as the baby is passing through the vagina on the way out, so to speak, where the baby picks up the bacteria there.

(06:02): But the biggest risk is the bacteria going up into the uterus after the water is broken. So we found out in the mid 1980s or so, there was some very good studies that showed that giving IV penicillin or ampicillin during labor to moms who carry GBS protected their newborns from developing early onset GBS and that's GBS infection that's within zero to six days of life. There's also a later onset GBS, but this is not what this test helps prevent. This is to help prevent early onset GBS infection and that's zero to six days of life. So based on this evidence from these studies in the eighties, the Centers for Disease Control published guidelines for preventing neonatal GBS disease they were published in 2010, was the most recent guidelines that the CDC published. However, the guidelines have been updated over time and the responsibility for updating those guidelines has been transferred from the CDC to acog.

(07:12): ACOG is the American College of Obstetricians and Gynecologists. It's an organization that sets guidelines and standards for our specialty. And these guidelines had a bigger update in 2019 and the reaffirmed in 2022 and acog, also the a American Academy of Pediatrics as well as the American College of Nurse Midwives endorse these guidelines. And the key intervention of these guidelines is intrapartum. So that means during Labor IV antibiotics for women whose babies are at risk of developing early onset GBS infection, and then our goal is to determine which of those moms are at risk and should receive the antibiotic. So that is what the testing is about. Now, there are two ways to look for GBS. There is risk-based approach and a culture-based approach. So there's a risk-based, and I'm going to go through that in a minute to determine whether or not you're at risk for having GBS and then culture-based go through that as well.

(08:20): Now in the United States, we do a culture-based approach found over time because we used to do risk-based back in the day like many years ago. But we found over time that approximately half of the cases would be missed if just a risk factor-based approach was taken. So in the US we do a culture-based approach, but let me tell you first about what the risk-based approach is. So the risk-based approach basically means we look for risk factors that if they are present, this is an indirect means of identifying women whose babies are at an increased risk of developing early onset GBS. So the things that we look for in that risk-based approach are a fever during labor greater than 100.4 degrees Fahrenheit. That's 38 degrees Celsius. We often use Celsius in medicine. If your baby is being born before 37 weeks, that increases the risk. If your water has been broken for more than 18 hours, then that increases the risk.

(09:30): Other things that increase the risk, or if you have a previous baby of an infant that had GBS disease, then we're definitely in future pregnancies going to automatically treat. And the other situation is if you have GBS in your urine and a current pregnancy, then we're going to automatically treat. We don't do the culture based approach, and I'll explain that again in just a minute. Now, these risk factors in the US are typically used if for some reason we haven't done the culture based screening yet. Okay, so these are only used if we haven't done the culture based screening. A common scenario is because the culture-based screening isn't done until late third trimester. If you're preterm, then you're automatically going to get treated for GBS because that's going to put you at an increased risk. Okay? So if for some reason the test hasn't been done, then these are the risk factors that we, or we don't even do the test if you had a baby that was previously affected, or if you have GBS in your urine, and again, I'll explain why in just a minute.

(10:34): Now, the culture-based approach, and that is universal prenatal culture-based screening, that is what we do in the US screening from maternal GBS colonization and then giving IV antibiotics during labor together that constitutes the most effective strategy for reducing any morbidity and mortality secondary to GBS. This regimen actually has been associated with a significant decrease in the incidence of GBS early onset disease and it really hasn't been associated with many adverse effects in women or newborns, although I'm going to talk a bit about how it affects the microbiome in just a minute. So the way that that works is that we recommend, or ACOG recommends GBS Rectovaginal screening cultures for all pregnant women between 36 weeks and 37 weeks, six days, okay? It used to be a little bit earlier, 35 weeks to 37 weeks, but now when I first did the episode, that's what it was, but now it's 36 weeks to 37 weeks, six days, and cultures are performed near term because many women have transient or intermittent colonization.

(11:58): So A GBS swab that's positive early in pregnancy may not be predictive of the status later in pregnancy. And we really want to check closer to term because at highest risk of transmission is during the labor process. So we're going to do those cultures between 36 weeks and 37 weeks and six days, and those results are valid, considered valid for five weeks. So if we test it 36 weeks, then you're going to be valid. Those results are going to be valid up until 41 weeks. And so that's why we do it during that timeframe. We do it with every single pregnancy because it can change with every single pregnancy. Colonization can vary. Actually 50 to 60% of women who are colonized in one pregnancy will not be colonized in the next pregnancy. So we really check every single pregnancy to see if you are a carrier for GBS, there are two circumstances where I mentioned where we don't do it.

(13:01): We don't do it. If you have GBS found in your urine during your current pregnancy, even if it's treated and a repeat culture has shown that the GBS has gone away, and the reason that we don't do it and consider you positive and needing treatment for GBS during your labor, even if we treat it during pregnancy, is because finding GBS in your urine is a marker for heavy colonization. Okay? That means you have actually a lot of GBS in your system and treating the urine does not eliminate it in the vagina or the rectum. So it doesn't eliminate it in the gastrointestinal and genital urinary tract. So if you have GBS in your urine at all during your current pregnancy, we are going to recommend that you get treated during labor. Also, we don't test it for women who previously gave birth to an infant that had GBS disease because you're considered if your baby had it once, then you are at risk again and we're going to err on the side of caution and we're going to treat you because your prior baby got sick.

(14:11): So we're definitely going to give it to you again. Now, the way that these swabs are done, they're little Q Q-tips, swabs, again, 36 weeks to 37 weeks, six days. They should be done before a digital exam to check your cervix. So we shouldn't do an exam with the gel and all that stuff and then do the GBS. We should do the GBS swab first. No lubricants are needed or shouldn't be done with the test. Again, it's a small Q-tip. Most people are fine with it. It's not terribly uncomfortable. Sometimes it can feel maybe like a little scratchy for some people, but it's just a little tiny q-tip swab, and it goes in the lower third of the vagina and then goes in the rectum, ideally through the rectal sphincter. So a little bit inside of the rectum. We don't need to use a speculum, we don't need to swab all the way up to the cervix.

(15:03): We don't need to swab the urethra, which is the opening to the bladder. It's just in the lower part of the vagina and then the rectum through the sphincter and the specimens can be obtained by your doctor or either you studies show that self sampling is just as accurate. So if you feel more comfortable sampling yourself, then ask if it's okay for you to do this sample. Some people are like, look, doc, what am I paying you for if you ain't going to be doing these tests and whatnot? So I totally understand if you want your doctor to do it, but if you fall into that category, which is also perfectly reasonable that you would prefer to do it yourself, then that is certainly appropriate and the results are going to be just as accurate. So then once that swab is done, it's sent to the lab and literally they swab it out on an old fashioned plate kind of thing and see if it grows GBS.

(15:55): The results take 48 hours to come back. They are not a 100% accurate. They're pretty accurate. About 4% of women will have a false negative when they actually do have GBS, but for the most part, the test is pretty accurate. Now, there are a couple of caveats to the testing. If you have a truce and severe penicillin allergy, then we have to do some special things because the treatment for GBS is penicillin. That's the preferred treatment. Next is ampicillin, but if you have allergy to penicillin, you're going to be allergic to ampicillin. That's a penicillin family of medicines. So if you have a penicillin allergy, then it's really important that when they do the test, they check and see if the GBS can be treated by another bacteria, another antibiotic, rather, something called clindamycin. Okay? Clindamycin can also treat GBS and it's safe to use in pregnancy.

(16:54): Now, the reason we don't use Clindamycin right off of the bat is because 20% of GBS bacteria are resistant to clindamycin. That's a high number. So we don't use it just right off the bat. So what we do is if you have a penicillin allergy, then we mark it on the form that you're allergic to penicillin. They have to do susceptibility testing to Clindamycin, and it's really important they don't do it automatically. They only do it if we mark it. So we have to be careful to market. So definitely bring it up. If you have a penicillin allergy, mark it on the form, and then the lab will test it to see if it is sensitive to clindamycin, if it's sensitive to clindamycin, and then you will get Clindamycin during labor instead of penicillin. If for some reason it's not sensitive to clindamycin, which does happen, then the only antibiotic that we have left is something called vancomycin.

(17:52): Okay? And I'll talk a little bit more about the treatment during labor in just a minute. Now, there's also a rapid GBS test that is available, and that can give results in less than two hours. Labor and deliveries do have that rapid GBS test. If for some reason we don't have the results. However, the test is expensive. Also, we can't do that susceptibility testing to see if you have a penicillin allergy, if it's susceptible to clindamycin. The test is also not as accurate, the rapid test. So it's not recommended to use it routinely, and I would say a lot, maybe most hospitals do not have the test. Moving on to risk factors for GPS, researchers have looked at risk factors for GBS and some of the things that we or that may increase your risk of carrying GBS are if you have multiple sexual partners, if you do male to female oral sex, if you have sex, frequently, heavy use of tampons can increase your risk of GBS.

(19:01): Infrequent hand washing can increase your risk of GBS. And then if you are younger, so under 20 years old, those are things that can increase your risk of being colonized with GBS. Now, one of the things that I see come up a lot is are there things that people can do in order to clear GBS before the test is done? One of the things I've seen is people say putting garlic in the vagina to eliminate GBS before the test. That is not recommended because it's not known whether or not it's safe, it's not known the implications of that. So we don't recommend doing garlic in the vagina in order to eliminate GBS, but there is something that may be showing some promise in terms of reducing GBS colonization, and that is probiotics. So the use of probiotics to reduce group B strep colonization is definitely an area of growing research interest.

(19:58): Some studies have actually suggested some potential benefits, but the evidence is not strong enough yet that we routinely recommend that people should try probiotics in order to reduce the risk of GBS. What we currently know is that certain strains of probiotics, particularly lactobacillus, has been studied for its potential to reduce GBS colonization. It's known for promoting a healthy vaginal microbiome, and that might inhibit the growth of bacteria like GBS. They also may help, probiotics may help by competing with GBS for adhesion sites on the vaginal epithelium. That's just the tissue inside of the vagina, and they may also help produce substances that inhibit GBS growth and they may potentially enhance your immune response. So those are all potential benefits of probiotics. And let me back up and say a little bit about what probiotics are. Probiotics are essentially healthy bacteria or microorganisms that are introduced into the body for their beneficial qualities.

(21:15): Okay? So these are beneficial bacteria and the microbiome is the collection of bacteria, viruses, fungi that live in and on us. We have many, many, many times bacteria, fungi, and viruses that live in and on us as we do human cells actually. And we see more and more that changes in the microbiome can affect the health. You see it a lot in reference to gut health. And so this is one of the areas that probiotics can help with potentially is changing the vaginal microbiome in order to prevent vaginal health. Now, some small studies in clinical trials have shown that probiotics might reduce GBS colonization rates. There was a study published in 2020 that's found that a combination of lactobacillus bacteria did reduce GBS colonization, but there are other studies that have not found significant reduction in GBS with probiotic use. So thus far we're just not there yet of saying that probiotics are helpful.

(22:20): The results may vary because of different strains in the probiotics dosages, the study designs populations. So again, there's just a lot of work that needs to be done in order to nail this down. Probiotics are generally considered safe during pregnancy, but you want to be sure that you choose a high quality supplement and talk with your doctor or midwife before you start it, especially during pregnancy. Supplements are something that aren't necessarily regulated by the FDA, not necessarily aren't regulated by the FDA, so you have to do some work in order to make sure you find something that's high quality. So do check and make sure you take something that is reputable if you're going to decide to try and take probiotics. And even if you do use probiotics, they don't replace standard medical practice. So you still will need to be screened. And if you do come up positive, we're still going to recommend that you get antibiotics during your labor.

(23:24): But I do think we're going to get to a point where probiotics are incorporated into prenatal care, and not just for GBS, but maybe for preterm birth because there's some concerns, and this is an aside, there are some data that's showing maybe the vaginal microbiome and preterm birth have an association. So just stay tuned for more research about probiotics. So what happens if you are GBS positive? If you are GBS positive, then the recommendation is that you are treated during labor. We don't retest and see if it's cleared and look to see if it's negative. If we do it between 36 weeks and 37 weeks, six days and it's positive, then we're going to recommend treatment. And the way that it modifies your labor a bit is that when your water breaks, remember that's the barrier that's protecting the baby from the bacteria. So often I tell folks, if your water breaks and the fluid is clear, then you can stay at home if you're not in labor.

(24:30): But if your water breaks and you have GBS, then you should go ahead and head on to the hospital to get antibiotics started and the antibiotics need to go through the iv. Now, the reason you want to head to the hospital is because ideally you want to have antibiotic treatment at least four hours before delivery. Alright, so go ahead and head on to the hospital if your water breaks and you are GBS positive. Again, we treat with IV antibiotics because that route gets antibiotics to the placenta and baby and the amniotic fluid the fastest. The oral route for antibiotics doesn't work as well inside the muscle for antibiotics doesn't work as well. So it's going to be IV treatment has really decreased early disease by about 80%. So it really does work. And as I mentioned, it's going to be penicillin, sometimes ampicillin clindamycin if you're allergic to penicillin and it's sensitive to Clindamycin.

(25:31): If not, then we use the big gun, which is vancomycin, and I say big gum because it's a very powerful antibiotic, but that's the only one that we have left. If you can't be treated with penicillin or clindamycin. And we also go ahead and start the antibiotics because it's hard to predict exactly when delivery will happen, and we want it to be in your system four hours before birth. Now you don't have to stay hooked up to the iv, you can just get the IV connected, get the antibiotics, and then get disconnected so you can walk around. So don't feel like that because you're getting treated for GBS during your labor that you're suddenly going to be hooked up to an iv. You won't be able to move that kind of thing. That's not the case. You can just get hooked up briefly, get the antibiotics as they go in, and then move about and not be connected to the IV after that.

(26:23): Now, there is one situation where you don't have to get antibiotics even if you aren't GBS positive. And that is if you are having a scheduled C-section without labor in that instance, the risk of transmission is very, very low. So we don't give antibiotics during that circumstance. Okay? Another thing that people question or have concerns about inval ones for sure is the effect of antibiotics on the baby's microbiome. Alright? So antibiotics given to mom during labor can actually reduce the diversity of beneficial bacteria in the newborn's gut. And that can happen because antibiotics are going to kill all bacteria, so they're going to kill both harmful and potentially beneficial bacteria. And studies have shown that babies who are exposed to antibiotics during labor do tend to have lower levels of beneficial bacteria, such as lactobacillus, such as bifidobacterium, and there may be an increase in other bacteria including some not as positive bacteria species.

(27:30): Also, the initial colonization of the newborn's gut microbiome can be delayed if mom gets antibiotics. So what happens is that the antibiotics can potentially disrupt the transfer of mom's microbiome to the baby and the infant's gut flora, the infant's gut bacteria is heavily dependent on that transfer from mom. Like you are the first person who gives your baby the bacteria that colonize the baby's gut and whatever bacteria those are. And in addition to the discussion of how antibiotics can affect the microbiome. As an aside, something that's also discussed about how or what affects the baby's microbiome is vaginal birth versus c-section and how your baby can have different microbiome based on that. But getting back to GBS, we know that there are documented short-term changes in the baby's microbiome because of mom getting antibiotics during labor. However, the long-term consequences are really still being studied.

(28:38): There is some research that suggests that early life antibiotic exposure could be linked to an increased risk of developing conditions like allergy, asthma and obesity. But more research is needed to confirm these associations. There are some things that we can do in order to mitigate the risk of altering the baby's microbiome so early. One is that antibiotics really should just be used only when necessary. And following established guidelines to minimize unnecessary exposure, it is considered necessary for GBS and preventing GBS transmission. So this would be a case where it is appropriate. One thing that may be discussed with your pediatrician is probiotics. Probiotics may help in restoring the balance of the baby's microbiome, and especially for babies who are exposed to antibiotics during labor. Some studies do suggest that administering probiotics to newborns can promote the growth of beneficial bacteria support a healthier microbiome. So definitely discuss that with your pediatrician as well, and that one of the best ways to help mitigate when babies get antibiotics is breastfeeding.

(30:02): That is one of the best ways breastfeeding, whether that's pumping or at the breast, it's one of the best ways to support the development of a healthy gut microbiome. In infants, breast milk has beneficial bacteria and also prebiotics. So prebiotics are ingredients or food that actually helps promote the growth of beneficial bacteria in the intestines. So breast milk has bacteria and prebiotics that can help establish and maintain a balanced microbiome. So the longer you can breastfeed, the better that will be in order to combat if you got antibiotics during your labor. Definitely further research is needed in order to understand the relationship between antibiotics and the infant microbiome and to develop strategies about this in order to mitigate the adverse effects. But breastfeeding is going to be a good one. And then also talk to your pediatrician about probiotics for your baby. The last thing I want to tell you about is what exactly is early onset GBS disease in babies?

(31:14): Why are we even presenting this? So early onset GBS disease is not very common, and it has declined quite a bit because of using antibiotics during labor. In the early 1990, the incidence was 1.8 cases per 1000 live births, and that decreased to 0.24 cases per 1000 live births in 2016. So to put that into actual numbers, they're roughly about 4 million births a year. So that reduced the number from over 7,000 babies with early onset GBS to around a thousand. So that's a really big reduction. And early onset GBS disease can be pretty serious. It can cause sepsis or the ways that it show up or the ways that it shows up. Rather, 80 to 85% of babies with early onset GBS will have sepsis. Sepsis is infection in the bloodstream. Another 10% will have pneumonia, 7% will have meningitis, and these symptoms are going to appear within the first 24 hours of life typically.

(32:24): And early onset, again, is between zero and six days of life. Not very common, but when it does happen, it can be very serious. Baby is going to need antibiotics anywhere from 10 days to 21 days. Supportive care that's going to be like IV medicines to get fevers down, things like that. Transfusions for anemia. In some instances, babies need to be on a ventilator, and sometimes babies have seizures with this and they need to have seizures treated. The death rate from early GBS infection is two to 3% for full-term infants. So that's a pretty high number, and it's higher for preterm babies. And among infants who survive to hospital discharge, which most are the risk of mortality, those still remains elevated throughout the first decade of life. So in one study, the risk of mortality was approximately threefold higher in GBS infected children compared with uninfected children.

(33:31): So again, although the death rate of GBS is low infants with early GBS infection can have long-term problems, and they're at risk for developing serious long-term sequelae like cerebral palsy, intellectual disability, seizures, hearing loss, visual impairment, and they're at a higher likelihood of requiring hospitalization during the first five years of life compared with uninfected children. So even though this thing is rare, the potential complications are pretty high. So weighing those risk imbalances or risk and benefits rather of treatment and screening everybody for it and treating for it if you have it, we've landed on the side that it's better to treat during labor with antibiotics. The risk of that is pretty low rather than take the small risk of a baby getting a severe infection. So that's how we have landed on the treatment approach and the screening approach with that culture-based approach that we do right now.

(34:36): So just to recap, GBS colonization affects 15 to 40% of pregnant women. We use that culture-based approach, universal prenatal screening in the US every single pregnancy, and that's between 36 weeks and 37 weeks, six days. If your urine has GBS, then we don't test for it. If you have a prior baby that had GBS and we don't test for it, you're going to automatically or we're going to automatically recommend that you get treated during your pregnancy. The treatment is IV antibiotics during labor, either with penicillin or ampicillin. If you're allergic to those, then it's going to be Clindamycin or Vancomycin. We do know that treatment with antibiotics during your labor may affect your baby's microbiome, but breastfeeding can really help mitigate the negative impact on your baby's microbiome. Also, your baby taking probiotics, maybe something that is worth exploring. You can discuss that with your pediatrician.

(35:39): Okay, so there you have it. Please share this podcast with a friend if you find it helpful, and subscribe to the podcast in Apple Podcast, Spotify. Wherever you're listening to me right now, leave me that review in Apple Podcast and I will read it. I will check it out. I love to hear what you think about the show, and I may use it as a shout out on a future episode. Do check out the birth preparation course, my signature online childbirth education class that gets you calm, confident, and empowered to have a beautiful birth. You can learn all the details at drnicolerankins.com/enroll and use the code DRNICOLE and get an additional 10% off. So that's it for this episode. Do come on back next week and remember that you deserve a beautiful pregnancy and birth.