During my pregnancy, I was made aware of how routine the administration of antibiotics is for GBS. When I asked to discuss the long-term health effects of this process on mother and baby with an OB, the response was:
"Honestly, I don't know. My job is simply to get the baby out safely. I have not looked into that."
So, of course, I made it a point to do as much research as possible and share what I learned with you.
Let's start from the basics: What is GBS?
One in four women are carriers of Group B Streptococcus (GBS), bacteria typically colonizing the female reproductive system and/or intestines of healthy individuals. Approximately 1 in every 2,000 newborns delivered from women who are colonized with GBS contract the bacteria (Horsager, 2010).
Though the rate of transmission of GBS from mother to offspring is slim, infection for the infant can be very serious, potentially leading to complications such as sepsis, meningitis, and pneumonia or even potentially fatal due to complications of the blood, lungs, brain, or spinal cord (Horsager, 2010). Signs and symptoms of early-onset GBS colonization may cause fever and, much less frequently, breathing problems, seizures, lethargy, or poor feeding. Even with preventative measures, the rates of late-onset GBS transmission are remained steady since 1990 (Jahromi, 2008).
So, how do they test for GBS?
Testing on the mother for GBS colonization is typically conducted between 35-37 weeks gestation via a Q-tip sample collection. The bacteria are then isolated from the sample during laboratory testing in order to confirm a diagnosis. In the United States, if a mother tests positive for GBS and/or if she goes into pre-term labor (before 37 weeks gestation), if she has a prolonged membrane rupture (18 or more hours before delivery), or has a fever during labor, she is commonly given a full course of intravenous antibiotics (2 rounds) during labor in order to prevent transmission of GBS to her child. After birth, diagnosis of GBS colonization of infants who test positive via swab testing is confirmed by isolating the bacteria from a blood or spinal fluid sample during laboratory testing. Infants diagnosed with GBS are routinely treated with rounds of intravenous antibiotics as well (Allen, 2012).
What are the long-term health implications of antibiotic treatment for GBS?
Recent research has shown that antibiotics can drastically disrupt the intestinal microflora, causing disease and chronic health problems (Dethlefson, 2008). As there is no form of targeted delivery system, it has been well established that antibiotics not only kill the problematic bacteria, but the beneficial bacteria as well. Recent research has also shown that antibiotic use can impair the intestinal ability to properly break down food, create essential molecules, and absorb critical nutrients ,such as iron. This gut disruption leads to issues that affect every capacity of the patient’s health, including an impaired immune system (Asociación RUVID, 2013). Antibiotic treatment of mothers during pregnancy influences colonization of the gastrointestinal tract microbiota of their infants. Mouse models indicate that maternal antibiotic treatment during pregnancy and lactation results in profound alterations in the composition of the gastrointestinal tract microbiota in infants. Though future testing must confirm this effect in humans, the results indicate that the conclusions would be similar (Gonzales-Perez, 2016).
Additionally, newborn babies are still developing their own immunity and mostly rely on their mother’s breast milk for protection against foreign invaders after birth. Microbiota in the breast milk enhance immunity, liberate nutrients, and synergize with breast milk oligosaccharides to enhance intestinal barrier function while strengthening a functional gut-brain axis (Latuga, 2014). When these beneficial bacteria are diminished, the increased immune system vulnerability may cause serious complications for infants – not only in their first few months of life, but over their entire lifespan (Gonzales-Perez, 2016).
Though the administration of antibiotics for mothers who are GBS positive is incredibly routine, insufficient research has been conducted to determine the long-term health effects of antibiotic use on the gut microbiota of the baby of a GBS positive mother in utero and in vivo. As antibiotic use affects infant microbiota in the general population, there is significant support to assume that this would also be the case in the specific populations of GBS positive mothers and their infants, though future research must be aimed at illuminating these potential health issues. Considering the low rates of serious complications from GBS infection in infants and the potential problems from antibiotic-induced gut disruption, future research must also be aimed at how the routine antibiotic use weighs against the health cost in this population.
What are your thoughts on this topic? I would love to hear from you!
Jahromi, P.S., Poorarian, S., & Poorbarfehee, S. (2008) The Prevalence and Adverse Effects of Group B Streptococcal Colonization during Pregnancy. Arch Iran Med, 11(6), 654 – 657.
Allen, V.M. & Yudin, M.H. (2012) Management of Group B Streptococcal Bacteriuria in Pregnancy. SOGC Clin Pract Guide, 276. http://sogc.org/guidelines/management-of-group-b-streptococcal-bacteriuria-in-pregnancy/.
Dethlefson, L., Huse, S., Sogin, M.L., & Relman, D.A. (2008) The Pervasive Effects of an Antibiotic on the Human Gut Microbiota, as Revealed by Deep 16S rRNA Sequencing. PLOS. http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0060280. Accessed May 27, 2016.
Asociación RUVID (2013) Effects of antibiotics on gut flora analyzed. ScienceDaily. Retrieved May 27, 2016 from www.sciencedaily.com/releases/2013/01/130109081145.htm.
Latuga, M.S., Stuebe, A., & Seed, P.C. (2014) A review of the source and function of microbiota in breast milk. Sem Reprod Med, 32(1), 68-73.