In observance of Group B Strep Month, read about the bacteria that can cause complications during pregnancy and serious illness in newborns.
Group B streptococcus — also called group B strep (GBS) — is a common bacterium often carried in the intestines or lower genital tract. According to the Centers for Disease Control and Prevention (CDC), although GBS is usually harmless in adults, it can cause complications during pregnancy and serious illness in newborns.
Anne Regenstein, MD, an ob-gyn and Maternal Fetal Medicine specialist at the Kaiser Permanente San Francisco Medical Center, talks about the top three things to know about the bacteria and its health implications.
We All Could Have GBS
“Usually GBS is only talked about when a woman is pregnant, but the bacteria is found in all of our guts — both men and women. It’s usually harmless and people are often unaware that they have it,” said Dr. Regenstein.
She said that in rare instances the bacteria can cause health problems for a pregnant woman, including urinary tract infection, infection of the placenta and amniotic fluid, and pneumonia.
“GBS can spread to the baby during a vaginal delivery if the baby is exposed to fluids containing the bacteria. While only a few babies who are exposed to GBS develop an infection, those who are infected could develop life-threatening complications,” she continued.
Shortly after birth, complications for the baby could include pneumonia, meningitis, bacteria in the blood (bacteremia) and sepsis.
“It’s so important to test pregnant women for the bacteria between weeks 35 and 37 in their pregnancies,” she said. The test includes a swab of the vagina and rectum that is sent to a lab for testing. “If the test is negative, no action is needed. If it’s positive, you’ll be given antibiotics during labor to prevent the bacteria spreading to your baby. You’ll need to repeat the group B strep test each time you’re pregnant.”
It’s Not that Uncommon
About 25% to 30% of all healthy, adult pregnant women have GBS and will need intravenous antibiotics when they arrive at the hospital. It is best for a woman to receive antibiotics at least four hours before birth in order to destroy bacteria in the birth canal and reduce a baby’s risk of developing an infection. Taking antibiotics before labor doesn’t help since the bacteria can grow back quickly, said Dr. Regenstein.
“The antibiotic is also recommended if you previously gave birth to a baby who had GBS or if you had a urinary tract infection caused by GBS during your current pregnancy, which means you’re at higher risk of spreading GBS to your baby,” she continued.
Managing GBS Is a ‘Public Health Win’
“The good news is that there are significant efforts to decrease cases of GBS in newborns — there’s been an 80% decrease since the 1970s,” Dr. Regenstein added. “The recommendations provided by the CDC, the American College of Obstetricians and Gynecologists (ACOG), and the American Academy of Pediatrics (AAP) are extensive and detailed, and Kaiser Permanente adheres to them.”
Since 1996, ACOG and the CDC have recommended the use of antibiotics to prevent GBS transmission to the newborn.
“Between the early 1990s and 2014, the cases of early-onset GBS per 1,000 live births decreased from 1.7 to 0.25. These screening guidelines are really a public health win,” said Dr. Regenstein.
From 2010 to 2015, the Kaiser Permanente Northern California rate was about half that reported by the CDC (0.10 per 1,000 live births).
Dr. Regenstein adds, “Our integrated health care system and tools within our electronic medical record enable us to be extremely successful at adhering to the guidelines.”