Usually, between weeks 36 and 38 of pregnancy, your care provider will do routine screening for vaginal strep B.4 They check whether you are positive or negative for group B streptococcus — found in about 10-30% of women.1 But what is group B streptococcus (GBS)? And how does it affect you, your labor, and your baby? Here’s what you need to know.
*Disclaimer: This post is not written to be medical advice. As a birth professional myself, people ask me many of these questions. I wanted to provide the answers I have found through the years of supporting pregnant women, attending births, speaking to medical professionals and birth workers, and doing research. I always want to provide quality information that helps women feel more prepared before, during, and after pregnancy and birth. As always, consult with your care provider for further information.
What Is GBS?
Group B streptococcus (GBS) is a bacterial infection that naturally lives in the intestines and migrates down to the urinary tract, vagina, and/or rectum.10 (Group B strep isn’t an STD, or sexually transmitted disease.9) Both men and women can be “carriers” of or “colonized” with GBS.13 For most people, there are no symptoms of carrying the GBS bacteria.10
How Do You Get Tested for GBS?
It’s now the standard in the United States for all pregnant women to be routinely tested for GBS at 36 to 38 weeks during each pregnancy.4 (The levels of GBS can change during each pregnancy, so your results could differ from one pregnancy to another.14 This is why they check every pregnancy regardless of whether you were previously positive or negative.) Testing involves a swab of your vagina and rectum, which then goes to a lab to see if GBS grows.1,8,11 Your test results are usually available within 24 to 48 hours.9
NOTE: Always inform your care provider if you take any new antibiotics and/or use vaginal medications. These medications may cause false-negative or false-positive results.14
What Happens If I Am GBS Positive?
If you test positive for GBS, it means you are a carrier.9 This is nothing to be ashamed of! Nothing will change during prenatal visits (since the antibiotics given before labor begins are ineffective at preventing GBS transmission).2 The difference is that your healthcare provider will give you antibiotics during labor to protect your baby from contracting GBS during delivery.2
NOTE: If you are GBS positive, it does not guarantee that your baby will also test positive and become ill.8
According to the Centers for Disease Control and Prevention (CDC), if you’ve tested positive for GBS and aren’t high risk, your chances of delivering a baby with GBS are 1 in 200 if antibiotics are not given and 1 in 4,000 if antibiotics are given.2,9
If you are GBS positive, there are some risk factors you will need to watch out for because they may indicate a higher risk of delivering a baby with GBS. According to the American College of Obstetricians and Gynecologists (ACOG), those risk factors include:1
- Gestational age less than 37 weeks
- Babies who have a very low birth weight
- Prolonged rupture of membranes (less than 18 hours)
- Intraamniotic infection
- Young maternal age
- Maternal Black race
- GBS found in the urine
How Will GBS Affect My Baby?
According to the CDC, GBS is a leading cause of life-threatening infections in newborns.3,6 It can pass from mother to child before or during delivery, and it can appear within hours to days after the delivery of your child. The CDC and the American Pregnancy Association state that early-onset symptoms in newborns include:5,9
- Breathing problems
- Fever
- Difficult with feeding
- Irritability or lethargy
- Heart and blood pressure instability
- Gastrointestinal and kidney problems
- Blue tint to their skin
NOTE: Per the CDC, “[e]arly-onset disease used to be the most common type of GBS disease in babies. Today, because of effective early-onset disease prevention, early- and late-onset disease occurs at similarly low rates.”6
Late-onset GBS symptoms in newborns include:5,9
- Signs and symptoms occur from one week to three months after delivery
- Meningitis (a common complication associated with GBS infection in a newborn)7
How Can I Protect My Baby From Group B Strep?
The CDC recommends giving antibiotics every four hours (through an IV) during labor.2 Most doctors want you to have several rounds of antibiotics before your baby is born, but at the very least, one round four hours before your child’s birth.12 This is why most doctors don’t want you to labor at home for very long so that they can make sure you receive enough antibiotics.
The most common antibiotics given for GBS during labor are penicillin and ampicillin.2 If you have a penicillin allergy, you will probably be given cefazolin, clindamycin, or vancomycin since these are alternative antibiotics.1
Do I Need To Be Treated for GBS If I Am Having a C-Section?
For C-section births, if you are GBS positive and labor has not yet begun (and/or your water hasn’t broken), you don’t need to receive treatment for GBS during delivery. However, if you are GBS positive and labor has begun and/or your water has broken, you will still have to receive treatment for GBS even if you have a cesarean delivery.4,14
Frequently Asked Questions (FAQ) About Group B Streptococcus (GBS)
Hopefully, the information in this article gave you a better sense of what group B strep is, how it could affect your baby, and its treatment. Remember to talk to your healthcare provider for more information.
