Protect Your Baby from Group B Strep
All pregnant women should get a group B strep (GBS) test when they are 35–37 weeks pregnant. Babies can get very sick and even die if their mothers pass GBS bacteria to them during childbirth.
All Pregnant Women Need a GBS Test
If you are pregnant, talk with your doctor or midwife about getting a GBS test. It doesn’t matter if you did or did not have this type of bacteria before; each pregnancy is different. CDC recommends getting it when you are 35–37 weeks pregnant. The test is an easy swab of the vagina and rectum that should not hurt. There are no risks to you or your baby from a GBS test. The test shows if you are carrying GBS bacteria, which you can pass to your baby during childbirth.
Women Who Test Positive for GBS Bacteria Need Antibiotics during Labor
If you test negative, you do not need to do anything more. However, if you test positive, you need an antibiotic (usually penicillin) through an IV (in the vein) during labor. If you are allergic to penicillin, there are other antibiotics to help treat you during labor.
CDC recommends taking the medicine during labor in order to prevent the bacteria from spreading to your baby during childbirth. Taking antibiotics before you go into labor will not protect your baby because the bacteria can grow back quickly.
Don’t Delay Going to the Hospital If You Are GBS Positive
The antibiotics work best if you get them for at least 4 hours before you deliver. So if you test positive for GBS bacteria, go to the hospital when your water breaks or your labor starts. If you think you might have a C-section or go into labor early (prematurely), talk with your doctor or midwife. Together, you can make a personal GBS plan.
If you have not had the GBS test when labor starts, tell the labor and delivery staff.
Talk with your doctor about a GBS test when you are 35-37 weeks pregnant.
Many Women Carry GBS Bacteria
GBS bacteria are common. They can live in the vagina and rectum of healthy women of all races and ethnicities. In fact, about 1 in 4 women in the United States carry this type of bacteria. These bacteria can come and go naturally in the body.
Testing Positive Doesn’t Mean You Are Sick
If you test positive, it does not mean you have an infection. It only means you have these bacteria in your body. You would not feel sick or have any symptoms. GBS bacteria are usually not harmful to you. However, GBS bacteria can make your newborn sick if you pass them to your baby during childbirth. Other people that live with you, including other children, are not at risk of getting sick from GBS bacteria.
Testing positive for GBS bacteria does not mean that you are not clean. It also does not mean that you have a sexually transmitted disease. The bacteria do not spread through food, sex, water, or anything that you might have come into contact with.
- Get a free fact sheet on GBS
- Download or listen to a podcast
- Healthy Pregnancy Information from CDC
Preventing Group B Strep
Information for patients, hospital and healthcare professionals, laboratory personnel, and state and local health departments about how to prevent GBS disease
- For Healthcare Professionals: Free Prevent GBS App for iOS and Android devices
- Page last reviewed: July 23, 2018
- Page last updated: July 23, 2018
- Content source:
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases
- Page maintained by: Office of the Associate Director for Communication, Digital Media Branch, Division of Public Affairs