Understanding Group B Strep in Pregnancy


During my 34th week of pregnancy I thought nothing of it as my obstetrician took a swab for Group B Strep. This was after all my 4th pregnancy and the test had always come back negative in the past. As a part of routine prenatal care, this test is performed on all pregnant women between their 34th and 37th week of pregnancy. Much to my surprise, the positive result at my 37 week visit along with the blasé attitude of my doctor and nurses threw me into a whirlwind of research. Between the internet, 2 doulas, my older children’s pediatrician, and a very helpful certified nurse midwife in Israel, I was able to make an informed medical decision for both myself and my baby.

Unfortunately for women in this country, prenatal care is addressed as a universal standard of care rather than on an individual basis. As my nurse stated while she walked me down the hall to my exam room, the Group B Strep positive result “is no big deal, it just means you will get antibiotics through your IV during delivery.” No other options were given and my questions were brushed off with the usual “this is the standard of care” response. For some, this seemingly simple answer would have reassured them all was fine, but for others like myself, red flags were raised.

If you are expecting or TTC, here is what you need to know about Group B Strep to make an informed medical decision for you and your baby.

Facts about Group B Streptococcus (GBS)

  • GBS can cause illness in people of all ages.
  • This bacteria is normally found in the vagina or rectum of 25% of healthy, adult women.
  • GBS bacteria lives in the intestines and migrates down to the lower 2/3 of the rectum which is why there is a frequent presence in/transfer to the vagina.
  • This is NOT a sexually transmitted disease; GBS is not passed between sexual partners.
  • For adults or carriers of GBS the bacteria usually come and go without symptoms.

Pregnant women are tested for GBS towards the end of their pregnancy because these bacteria can cause serious complications in newborn babies. Sepsis, meningitis, and pneumonia during a newborn’s first week of life, usually with onset during the first 48 hours outside the womb, are the most common concerns. The risk of babies developing GBS occurs if the infant swallows amniotic fluid containing the bacteria into their lungs during delivery. Women are tested with every pregnancy because of the transitory nature of GBS; you may be positive in one pregnancy and negative the next. Also, if a woman has a GBS+ result at any time during pregnancy she is treated as positive at delivery with no retest. However, if she is negative and does not deliver within 4 weeks she must be retested.

According to the Centers for Disease Control and Prevention:

  • The standard of care for a woman with a positive GBS test result during her 35th-37th week of pregnancy is IV antibiotics during labor.
  • The most commonly used antibiotic is penicillin unless the mother is allergic.
  • For optimal results antibiotics should be given every 4 hours, preferably beginning at least 8 hours before delivery (2 doses).
  • GBS + mothers who receive the optimal dose of antibiotics have a 1 in 4,000 chance of delivering a baby with GBS disease.
  • GBS + mothers who do NOT receive antibiotics have a 1 in 200 chance of delivering a baby with GBS complications or disease.
  • If a baby is born to a GBS+ mother WHETHER SHE HAS RECEIVED IV ANTIBIOTICS OR NOT the American Academy of Pediatrics Red Book states the baby is to be monitored for 48 hours.

Depending on where you live there are 2 different medical approaches for labor and delivery for a mother with a GBS + result – the Universal Approach (United States & Canada) and the Risk-Based Approach. The Universal Approach used in the United States is to provide IV antibiotics to GBS+ women at the onset of labor. The Risk-Based Approach (United Kingdom & New Zealand) takes several factors into consideration:

  • Premature delivery at less than 37 weeks.
  • Length of time from the rupture of membranes to delivery (18 hours +).
  • Fever of the mother during delivery.
  • Prior baby born with GBS complications.
  • GBS in the mother’s urine during pregnancy because this signifies a higher amount of bacteria present.

Prenatal screening and antibiotic use for GBS became more prevalent in the medical community in 1996 per the CDC’s recommendations; however, it was not until 2002 that the CDC began recommending the universal approach in all cases of GBS + mothers. Currently in the United States, the risk-based approach is only used in the doctor’s discretion when a mother presents in labor and does not know whether she is positive or negative.

There is also a rapid, in-labor test performed at the hospital which is currently used in France. However, this test is expensive and some argue wastes time that a woman could be receiving antibiotics. On the other hand, studies have shown the rapid test reduced the rate of people unnecessarily treated with antibiotics from 14% to 5%.

What does this mean for Group B Strep + Pregnant Women?

Parenting decisions never come easy and for many of us this is not one to be taken lightly. The risks are high both with and without antibiotics. The overuse of antibiotics in recent years has led to an increase in antibiotic resistant bacteria and superbugs which should concern us all. Never before have we been more aware of the importance of healthy gut bacteria and allowing our bodies to develop immunities to everyday invaders. As a mother, this is just one of the first, difficult medical decisions involving antibiotic use you will make for your baby. Further, as your doctor will likely suggest the “standard of care” as mine did, rather than a personalized approach, it is up to you to make an informed decision.

For myself, the antibiotic use was a serious concern for several reasons: my husband suffers from Crohn’s disease, making my children’s microbiome of utmost importance to me, I was going to deliver in a public hospital during one of the worst flu seasons on record, and I had 3 children at home who would all continue attending school daily during said flu season. Further, I have never been in labor for more than 2 hours making the efficacy of the antibiotics basically non-existent.

While there are always risks associated with antibiotic use, pregnant mothers should be especially concerned with their infant’s microbiome. The large dose of antibiotics given during delivery to prevent GBS crosses the amniotic sac to your baby. In killing off the “bad” GBS bacteria, the antibiotics are also killing the “good” bacteria your baby has acquired during gestation and will acquire during the trip down the birth canal.

Studies have shown that even at one year after birth, breastfed babies whose mothers receive antibiotics at the time of delivery are still lacking in beneficial bacteria and the “richness” of their microbiome as compared to those who did not receive any form of antibiotics at delivery. Further, not only are baby’s beneficial bacteria destroyed alongside the GBS, but this can also lead to an overabundance of negative bacteria growth.

While antibiotics may be the suggested course of treatment with a GBS+ result there are alternative options out there. Both the Garlic Vaginal Protocol and the Hibiclens Protocol have been successfully used by midwives for years. Unfortunately, the effectiveness of these alternatives has not been widely tested because of the prevalence of antibiotic use along with the low cost per capita ratio of administration. However, with the increase in concern regarding antibiotic overuse and the position of the World Health Organization on tackling antibiotic resistance hopefully the future will involve the consideration of these options.

Personally, after following the Garlic Vaginal Protocol for 2 weeks and demanding a re-test from my obstetrician I tested negative for GBS two days prior to my delivery. As an added precaution I also completed a Hibiclens Protocol once at the onset of my contractions. I also decline vaginal exams at this stage of pregnancy as they are generally unnecessary and in the case of GBS can actually push the bacteria closer to baby. Luckily, the alternative methods worked as I delivered my son as I expected exactly 2 hours after arrival at the hospital.

There is no greater gift than that of becoming a mother, but there is also no greater responsibility. Along with your partner or spouse you have choices to make for you and your baby if you receive a GBS+ result. As much as our doctors may have the best of intentions, the standard of care is a universal approach that is truly not one size fits all. That said the information is out there so simply do your best to make the most informed medical decision for you and your little one as you begin this adventure called parenthood.

Expecting parents often have a host of concerns regarding their baby’s health and development. If you have specific concerns you may want to consider the option of Prenatal Genetic Screening, is it for you?

Sources: Centers for Disease Control and Prevention, Evidence Based Birth, Midwifery Today, Peaceful Parenting

Photo Credits: Kristen Lee Creative, Kristin dePaula

Leave a Reply

Your email address will not be published. Required fields are marked *