Group B Strep (GBS)

black and silver stethoscope on white surface

Taking a look at Group B Strep and how it may affect your labor.

Group B Streptococcus (also called Group B Strep or GBS) is bacteria found in the mother’s vagina, rectum or even in the urinary tract. It is found in 10-30% of healthy pregnant women and may be considered normal vaginal flora in a woman who is not pregnant. If the baby comes in contact with GBS while the mother is in labor, especially after the mother’s water has broken, the baby can become infected.

Babies who become infected require a longer stay and antibiotic treatment. 1 or 2 babies out of 100 will become infected by Group B Strep. Even though the chances are small, GBS can become life-threatening to the newborn. What are other questions women have about Group B Strep?

When will I be tested for GBS?

Most women are screened for GBS around 35-37 weeks of pregnancy at your routine prenatal visit. Your doctor or midwife will take a swab from your vagina and rectum and results are then sent to a lab. Typically you will get results from the culture at the following visit or in 1-2 days.

What happens if I test positive for Group B Strep?

If your lab work comes back positive, then CDC guidelines recommend antibiotics through an IV approximately every four hours during labor to treat Group B Strep. Typically penicillin or ampicillin is used so be sure to discuss any allergies to these antibiotics with your provider.

Are there any side-effects from GBS treatment?

The only possible side affects might be slight stinging from the IV antibiotics as the medication enters your bloodstream. Also some women might be senstive to antibiotics and develop yeast infections or thrush. Check with your provider to see if there are ways to prevent or treat these yeast infections.

Can I refuse antibiotic treatment for positive Group B Strep?

As with any medical procedure or treatment, it is your right to refuse antibiotics. However keep in mind that it is much easier to treat the you with antibiotics during labor than it is to treat your baby. A CDC study showed that 90% of GBS infections can be prevented by treating the mother with IV antibiotics in labor.

What happens if I don’t know my GBS status when I go into labor?

If you have not had the Group B Strep culture taken when you go into labor, some providers will recommend that the mother still be treated if she has certain risk factors that might be an indication that she could pass Group B Strep on to her baby. The risk factors are:

  • Pre-term labor (before 37 weeks)
  • Fever (100.4 degrees or higher)
  • Prolonged Rupture of Membranes (longer than 18 hours)

If I am GBS positive with the first pregnancy, will I be positive again with later pregnancies?

Many providers will assume that if the mother carries the Group B Strep bacteria, there is a chance that she could have it again and so it will need to be treated. Also if a woman has ever had GBS in her urinary tract, she will need to be treated.

If I am having a scheduled cesarean, will I need to be treated for Group B Strep?

Unless your labor starts or your water breaks, you will not need to be treated with antibiotics for GBS. However some providers do routinely treat mothers with antibiotics after a cesarean as prevention for infection.

Click here for more information about prenatal tests.

What was your result from the Group B strep test? Tell us about it.