Pregnancy is a time when you should relax, take care of yourself, and avoid stress. It saddens me that so many of the procedures used in routine obstetrical care increase stress without adding benefit. I've been thinking about Group B Strep recently because a pregnant mom I know will soon be required to undergo testing for this common bacteria. In the UK, pregnant women are not routinely screened for GBS, primarily because colonization is extremely variable and there is a tendency for recolonization after treatment.1 Here is a great link that provides more information on Group B Strep: http://www.homebirth.org.uk/gbs.htm. If you don't have any risk factors present, you might want to consider whether or not testing for Group B Strep is the best decision for you. The CDC's protocols are "expected to reduce, but not eliminate, the incidence of neonatal infection."2 In other words, GBS testing does not guarantee an infection-free newborn and the risks of routine GBS testing and treatment of all GBS positive moms remain unknown (a few follow below). Interestingly enough, routine screening has not resulted in any decrease in late-onset neonatal GBS disease.3
Risk Factors (moms/babies who fall into the below categories have a higher risk of developing GBS disease):4
- Preterm babies (especially before 35 weeks, but also before 37 weeks. One recent UK study of risk factors found that 6 babies out of more than 62,000 born in the study period died of GBS infection; of these, 5 were born before 36 weeks (see ref 3).
- Mother having a fever during labour
- Prolonged rupture of membranes - over 18 hours
- GBS found in the mother's urine, not just the vagina
- Mother having had a previous child with GBS disease
- Rupture of membranes before 37 weeks
From Anne Frye, a few reasons to avoid the GBS test if no risk factors are present5:
- Some babies will become ill with GBS without any evidence of colonization from their moms.
- There are risks of fatal or severe side effects due to drug reactions.
- In many cases mom will transfer antibodies to fetus which will protect fetus from GBS infection (see http://www.ncbi.nlm.nih.gov/pubmed/768760?dopt=Abstract or http://www.jci.org/cgi/content/full/98/10/2308 for example). Instead of routine testing, why not a GBS vaccine?
- Antibiotic treatment may cause bacteria to develop mutations that will make them resistant to antimicrobial treatments.
A few completely random thoughts... 10-30% of all women have already been colonized by GBS bacteria and studies have shown that many colonized women pass on the antibodies that protect against GBS infection to their infants. If almost a third of the female population is colonized by GBS, women probably had to come up with a mechanism of protecting their young (thus the transfer of antibodies) or natural selection would have weeded out moms colonized by GBS, right? So what will happen if we continue to routinely test for Group B strep and administer antibiotics to all GBS positive moms, regardless of risk factors (a relatively new practice)? Will our immune systems be compromised? Will bacterial mutations render the antibodies that protect our infants from GBS ineffective? Hospitals have loads of bacteria and procedures such as more then 12 hours of continual monitoring and more then six vaginal exams have already shown to increase the risk of active infection.6 Will babies be at an even increased risk of infection, having lost some of the natural immunity passed from their moms? Oh how I miss my student days when I would have an idea and carry out a research project to further explore my questions. I am looking forward to being back in school (I will start taking online classes shortly) and diving into research again.
For Further Reading:
And I LOVE this paragraph from Henci Goer on infection rates for GBS Strep:
By the way, we do not know what GBS infection rates would be if clinicians kept their fingers out of the vaginas and and monitoring devices out of the uteruses of GBS positive women with ruptured membranes because we have no studies of which I am aware where vaginal exams and internal monitoring were avoided. The GBS organism comes from the rectum and is usually limited to the lower part of the vagina in colonized women where it is harmless to babies. It is possible that avoiding giving the bacteria a free ride on the examiner's finger or through internal EFM or contraction monitoring would be equally effective without the downside of antibiotic treatment. We'll never know because IV antibiotics do work, which leads to the question: If doctors had had antibiotics in Semmelweis' time, would they be washing their hands today?
In the end, the decision to test or not is yours. As a mom I know recently noted so wisely, in the end most of us (normal birth junkies and the medical community alike) are just trying to control birth but the harsh reality is that we can't. Neither GBS testing, nor cesarean for reasons of breech presentation, nor the best fetal monitoring will guarantee a healthy baby. What you can do is be informed, take care of yourself during your pregnancy, prepare your body/mind for birth, and trust birth.
1 Diane M. Fraser and Margaret A. Cooper, Myles Textbook for Midwives (London: Churchill Livingstone, 2003)380.
2 Anne Frye, Understanding Diagnostic Tests in the Childbearing Year (Portland,Oregon: Labrys Press, 1997)574.
937fbf1f44d856b0e875001a08c0b9 (Accessed Jan 3, 2008)
5 Anne Frye, Understanding Diagnostic Tests in the Childbearing Year (Portland,Oregon: Labrys Press, 1997)569-578.
6 Anne Frye, Understanding Diagnostic Tests in the Childbearing Year (Portland,Oregon: Labrys Press, 1997)573.