Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

baby in incubator


Occasional Science & Sensibility contributor Rebecca Dekker of Evidence Based Birth has spent the last month writing a blog article about Group B Strep and it is finally here! In her painstaking but clear review of the evidence on GBS in pregnancy, Rebecca came to the conclusion that universal screening and treatment for GBS is more effective than treating with antibiotics based on risk factors alone. She also found that although “probiotics, chlorhexadine, and garlic have the potential to reduce vaginal and newborn colonization with GBS, we do not have evidence yet to show that these strategies can prevent early GBS infections, since GBS infection usually occurs when GBS gains access to the amniotic fluid and gets into the fetus’s lungs during labor.”

To read Rebecca’s just released article, Group B Strep in Pregnancy: Evidence for Antibiotics and Alternatives in its entirety, click here.

Today, Rebecca joins us on Science & Sensibility to talk about her latest addition to Evidence Based Birth.

Sharon Muza: What inspired you to write this article?

Rebecca Dekker: I received more requests to write about Group B strep than any other topic! Over the past few months, I had weekly, sometimes daily emails and Facebook messages from women—all asking me to provide them with evidence about antibiotics, hibiclens, or garlic for preventing GBS infections. After about the 50th request, I figured I better set aside my other plans and focus on this topic, because it was clearly weighing heavily on many women’s minds! 

SM: What was the most difficult thing about writing this article?

RD: Probably the most difficult thing was sorting through the stacks and stacks of research articles that have been published about Group B strep in pregnancy. This was one of the reasons it took me almost a year of blogging before I decided to dive into group B strep. I knew it would be a monumental task. And it was. But I was fortunate enough to have an expert in GBS who helped point me to the most important or “landmark” studies.

SM: Who was this expert?

RD: I met Dr. Jessica Illuzzi via email earlier this year. She and I had corresponded about a different blog article, and at that time I found her to be incredibly helpful. I knew that in addition to being an OB, Dr. Illuzzi was a research expert in GBS. So I asked her if she would review my article for me. To be honest, I could not have written this article without her guidance. She read my first draft and basically told me that I needed to go back to the drawing board. She encouraged me to dig deeper into the evidence so that I would really understand it. Whenever I had questions about something, she sent me research articles that immediately answered my question. In the end, I knew the article was ready when she said it was a great summary of the state of the science of GBS. 

I was also lucky enough to have 2 other GBS experts give me feedback on the article—a GBS researcher and a microbiologist. And then I have several physicians who faithfully review all of my articles and give great suggestions. I am very grateful to all of them as well!

SM: I know that you usually begin your articles with an exploration of your own biases, in order to tease the bias out of your writing. Did you have any pre-existing biases about GBS? 

RD: To be honest, I actually had no biases up front. I was fortunate to always test negative for GBS myself, and so I never had to struggle with this issue before. I was pretty open-minded to the entire issue. I was open-minded to antibiotics. I was open-minded to hibiclens or other alternatives. I had no personal agenda. I simply wanted to get to the facts. Hopefully this lack of bias will shine through and help people respect the article even more.

 SM: What surprised you most as you wrote this article?

RD: One of the things that surprised me was how people have such different reactions when they read the evidence about GBS. I had several friends preview the article for me. Some of them instantly said, “Oh yeah, that sounds like a really high risk. I’d definitely take the antibiotics to prevent an infection in my newborn.” Others would say, “Really? That’s all? That’s not a very high risk at all. I wouldn’t take antibiotics for that level of risk.” This is a great example of how everyone perceives risk differently. But at least in this article I have been able to put some evidence-based facts out there. Let people interpret the risks as they may. I only ask that they talk with their health care provider before making any decisions!!

 SM: What do you think is the future of GBS evidence?

RD: Ten years from now I am guessing that I could write a very different article. I would like to think that by then we may have a vaccine on the horizon that could prevent both early GBS infections and GBS-related preterm birth. It would also be nice if the rapid test was affordable and widely available by then. I would also LOVE to see some solid research evidence on the use of probiotics for decreasing GBS colonization rates in pregnant women. As far as I know, probiotics for decreasing GBS hasn’t been studied yet in pregnant women, and I think it deserves further inquiry.  

SM:What makes your blog article about GBS different than all the other blog articles out there on this topic?

UK College of Nursing Faculty, 082310

Rebecca Dekker

RD: I purposefully didn’t look at any of the other GBS blog articles out there until I finished my article. Yesterday, I read through a variety of blog articles (there are a lot!). Most of them were about 90-95% accurate in their facts. A couple of them had serious errors (in particular, I found one blog article that had inaccurate information about hibiclens). Most didn’t list any references, and I could tell that most of the blog authors had used secondary sources (other blogs or summary articles) instead of looking at the research evidence themselves. This can be fine, but sometimes it’s a bit like playing telephone: You just keep repeating the same facts over and over without checking to see if the evidence has changed or if the summary you are parroting was accurate in the first place. I’d like to think that my blog article is a very accurate assessment of the research evidence on GBS in pregnancy—translated into regular language so that women and their family members can understand the evidence. 

SM: What are you going to write about next?

RD: I don’t know!! What would YOU like to see me write about?

SM: I want to thank you Rebecca, for your contributions to Science & Sensibility and for sharing Evidence Based Birth with the world!  I know that these articles take a huge amount of time and you are very diligent and conscientious about researching the literature and providing only the best analysis possible,  and seeking out experts on the topic to help you really be sure that you are offering the best of the best of information.  I always enjoy reading your blog and find it a great source of information for my doula and CBE students and my birth doula clients as well. I know that I speak for all the readers here on Science & Sensibility when I say, keep on keeping on!  Do please let Rebecca know what you would like her to write about next!   


Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

April 9, 2013 07:00 AM by Alicia
This was very interesting to me, and I appreciate the thorough information. For two pregnancies now, I have declined the test based on the research I did. I am compelled to make the same decision this time, largely because I am allergic to penicillin and am not comfortable taking the few alternatives preventatively (vs after a serious infection where it's clear abx are needed), in addition to future health consequences of antibiotics at birth. I wondered about women who tested negative, knowing status can change before birth, so I found this interesting too: "Most of the cases of GBS in term infants (61%) happened in women who had been screened but tested negative for GBS.". Lastly, my last labor was only 2 hours, and the midwife arrived an hour before the birth, no time for antibiotics. A potential harm that should be listed is the long term affects of receiving antibiotics with its effect on gut health, destroying good bacteria that can never be replaced. We have a large increase in gut related health problems in children, and antibiotic use is one of the culprits. My approach so far has only been to use antibiotics when necessary, and not as a precaution. I am not comfortable reducing the already small risk of GBS infection by accepting abx, and as a result inflict known damage on my baby's gut. I'm curious if there is a difference in the upward journey of the bacteria if is present in the vagina and not the rectum, and vice versa. Lastly, I'd be fascinated to learn any differences in infection between home births, which tend to have few vaginal exams, and hospital births, which tend to have more vaginal exams. I can't imagine there isn't some "help" received by pushing any bacteria farther up the birth canal, if those exams happen shortly after water breaks, and at the end of pregnancy with routine checks at OB offices, which is the same time this research has indicated early infection tends to occur (which makes sense if a baby would show symptoms as early as an hour after birth). Great article, good research - this will be helpful to many!

Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

April 10, 2013 07:00 AM by Jeanette McCulloch
Rebecca ~ thanks for this and all of your great posts. One post I'd love to see is a look at maternal age. When is a mother considered a high risk pregnancy? Does maternal age change the point at which an induction is medically recommended? Which prenatal tests are recommended?

Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

April 10, 2013 07:00 AM by Rebecca Dekker, PhD, RN, APRN, ACNS-BC
Thanks, Jeanette for the suggestion that I look at advanced maternal age. And Alicia, I appreciate the suggestion to look at the effects on gut flora. I did not include this because I did not find any studies that looked at a potential link between antibiotics for GBS and gut flora. But I will dig a little deeper and revise my article with whatever information I find.

Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

April 14, 2013 07:00 AM by Sarah
I'm glad someone did this research and didn't just use personal claims to prove their point. Glad to see that treatingfor GBS is more effective than using antibiotics

Evidence Based Birth Takes on Group B Strep: An Interview with Rebecca Dekker

April 24, 2013 07:00 AM by Utah Doula | Weekly Roundup of Web Links | Andrea Lythgoe Doula Salt Lake City Utah
[...] on Group B strep (Also called GBS or Group Beta Strep). And another of my favorite blogs features an interview with the author of Evidence Based Birth about the new [...]

A new GBS test

May 16, 2016 08:08 AM by Jacqueline Levine

I came across this info a few years ago, and have asked many an OB and many a hospital nurse whether they've ever heard of a test that can be done with good accuracy when a woman comes into the hospital in labor. Not one said they were aware of such a "new" test.  (Not the old one which is not that accurate.)  We test in weeks 36-38, but surely some women colonize late in pregnancy and have babies born through GBS without our ever knowing.  We now have a 20-minute tes for HIV .  It would be great to know GBS status at the time of labor, since the consequences of depending on a test done weeks before may be consequential:  unnecessary antibiotics (babies suffer more asthma with IV antibx even for mothers), or missing the rare baby who may really  have needed the prophylaxis. Is this test in use anywhere?  Here's the info I saw:




BJOG. 2011 Jan;118(2):257-65. doi: 10.1111/j.1471-0528.2010.02725.x. Epub 2010 Oct 13.

Intrapartum tests for group B streptococcus: accuracy and acceptability of screening.

Daniels JP, Gray J, Pattison HM, Gray R, Hills RK, Khan KS; GBS Collaborative Group.

Collaborators (16)

Edwards E, Barnfield G, Tenage M, Milner P, Thompson P, Spicer L, Howard R, King E, Magill L, Tyler E, Fulcher L, Buckley L, Elliman N, Roberts T, Kaambwa B, Bryan S.

SourceUniversity of Birmingham, UK. j.p.daniels@bham.ac.uk


To assess the accuracy and acceptability of polymerase chain reaction (PCR) and optical immunoassay (OIA) tests for the detection of maternal group B streptococcus (GBS) colonisation during labour, comparing their performance with the current UK policy of risk factor-based screening.

DESIGN: Diagnostic test accuracy study. SETTING AND POPULATION: Fourteen hundred women in labour at two large UK maternity units provided vaginal and rectal swabs for testing.

METHODS: \The PCR and OIA index tests were compared with the reference standard of selective enriched culture, assessed blind to index tests. Factors influencing neonatal GBS colonisation were assessed using multiple logistic regression, adjusting for antibiotic use. The acceptability of testing to participants was evaluated through a structured questionnaire administered after delivery.

MAIN OUTCOME MEASURES: The sensitivity and specificity of PCR, OIA and risk factor-based screening.

RESULTS: Maternal GBS colonisation was 21% (19-24%) by combined vaginal and rectal swab enriched culture. PCR test of either vaginal or rectal swabs was more sensitive (84% [79-88%] versus 72% [65-77%]) and specific (87% [85-89%] versus 57% [53-60%]) than OIA (P < 0.001), and far more sensitive (84 versus 30% [25-35%]) and specific (87 versus 80% [77-82%]) than risk factor-based screening (P < 0.001). Maternal antibiotics (odds ratio, 0.22 [0.07-0.62]; P = 0.004) and a positive PCR test (odds ratio, 29.4 [15.8-54.8]; P < 0.001) were strongly related to neonatal GBS colonisation, whereas risk factors were not (odds ratio, 1.44 [0.80-2.62]; P = 0.2).


Intrapartum PCR screening is a more accurate predictor of maternal and neonatal GBS colonisation than is OIA or risk factor-based screening, and is acceptable to women.

© 2010 The Authors Journal compilation © RCOG 2010 BJOG An International Journal of Obstetrics and Gynaecology.

PMID:21040389[PubMed - indexed for MEDLINE]


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