Friday, July 6, 2012

Ask an OB: Group B Strep, What the Research Says

Today's post is a special edition of Ask an OB, which is typically a weekly series.  Dr. Maude "Molly" Guerin, MC, FACOG, had some insightful thoughts to share  on the Group B Strep conversation. 

Is screening all women for Group B Strep just another example of doctors looking for problems that are not really there? I want to keep things as simple as possible for my birth and this seems optional to me. - On the fence mom 

Again, this is an excellent example of making an informed choice. Get the data from a reliable source, and decide for yourself what you want to do.

Here are the FACTS:
            • 20% of women carry Group B Strep as a normal part of their healthy vaginal   
              bacteria. It doesn’t hurt them and it is supposed to be there.
            • 1 to 2 out of every 100 babies born vaginally to women who carry Group B Strep 
              will develop sepsis, a severe infection from GBS, usually meningitis or pneumonia.
            • 20 - 50% of babies that get septic from GBS will die
            • Starting in the mid-1990s research showed that getting IV antibiotics during labor 
              reduced the risk of sepsis from 1 – 2 per 100 babies to 1 in 1000 babies. (Morbidity  
              and Mortality Weekly Report Recommendations and Reports,
              November 19, 2010 / Vol. 59 / No. RR-10)

Graph: Incidence of Early and Late Onset Group B Strep Disease

Research into using antiseptic vaginal douche (chlorhexidine) rather than IV antibiotics was initially promising because it appeared to reduce babies being born with GBS on their skin. Unfortunately the chance for sepsis did NOT go down with this intervention (Vaginal chlorhexidine during labour to prevent early-onset neonatal group B streptococcal infection Brenda C Stade1,*, Vibhuti S Shah2, Arne Ohlsson2 Editorial Group: Cochrane Pregnancy and Childbirth Group Published Online: 23 APR 2008).

So, let’s start with 1000 healthy pregnant ladies who deliver vaginally and are not screened for GBS. Statistically, 200 of them will carry GBS. Then 4 of those 200 babies will get septic. Then 1 or 2 of those babies will die. Alternatively you could be screened, and if positive for GBS get a heparin lock placed for an every 4 hour dose of antibiotic while in labor. Know the facts from a reliable source and make your choice.


  1. Is penicillin the recommended antibiotic for iv treatment during labor? If so, what is the recommendation for mothers with a severe allergy to penicillin?

  2. If you are penicillin allergic the lab will test other antibiotics against your positive culture and recommend safe alternatives

  3. If you are penicillin allergic the lab will automatically test your positive culture for alternative antibiotics that will be effective
    Good question!

  4. And if there is none? I'm deathly allergic to all cillins, and merely very allergic to sulfa drugs. Vanomycin, I've read, is an option but it has nasty side effects and isn't considered highly effective by the CDC.

  5. This comment has been removed by the author.

  6. Erythromycin and Clindamycin are options - we rarely have to use Vancomycin. We do the best we can!

  7. Do you have a breakdown of the babies at term who will be affected or is this an overall number from viability to 42 weeks?

  8. These numbers apply to all babies