What to know about Group B streptococcus while pregnant

by Kaiser Permanente |
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Group B streptococcus (GBS) is a naturally occurring bacteria that is sometimes found in the vagina and rectum. It’s estimated that about one in four women in the United States are carriers of GBS. It is not a sexually transmitted disease.

In healthy adults, it usually doesn’t cause any symptoms. However, GBS can be dangerous if it spreads to your baby during birth.

How could GBS affect your baby?

With current testing and treatment, GBS rarely affects either mother or baby. However, without treatment, serious complications are possible.

If your baby becomes infected during birth, GBS can cause sepsis (a serious blood infection) and pneumonia (an infection that inflames your lungs' air sacs). It can also cause meningitis, an infection of the brain lining and spinal cord. In rare cases babies can die from this infection.

How can you protect your baby?

Your clinician will test you for GBS between weeks 36 and 38 of your pregnancy. A positive test means you’ll receive antibiotics during your labor to prevent GBS from passing to your baby. Be sure to tell your health care team if you are allergic to penicillin or other antibiotics so an effective alternative can be chosen. If you had a urine culture that showed GBS at the beginning of pregnancy, you will already be considered positive and receive antibiotics when you give birth. If you had a previous pregnancy where the baby became infected, you will be given antibiotics during labor.

This article has been created by a national group of Kaiser Permanente ob-gyns, certified nurse-midwives, pediatricians, lactation consultants and other specialists who came together to provide you with the best pregnancy, birth, postpartum, and newborn information.

Some of the content is used and adapted with permission of The Permanente Medical Group.