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Group B Strep

Medically reviewed by Last updated on Oct 31, 2022.

What is a group B strep (GBS) infection?

A GBS infection is a condition caused by bacteria called group B streptococcus. GBS are normally found in the digestive organs or vagina. A person may carry GBS and not get infected and become sick. GBS may cause infections in the blood, lungs, or skin. GBS rarely cause serious problems in adults, but can be life-threatening to babies. An infection may cause preterm delivery, stillbirth, or an infection in the mother's womb or bladder.

How does a GBS infection happen?

  • Babies can get infected during birth, or shortly after. A baby may also become sick if he or she had contact with a person infected with GBS.
  • The bacteria are not easily passed to other adults. Among adults, GBS infection usually affects pregnant women and the elderly. An adult with a disease such as diabetes or cancer may also be affected.

What increases my baby's risk for a GBS infection?

A baby is more likely to be infected with GBS if his or her mother has any of the following:

  • Water that breaks before the 37th week of pregnancy
  • Fever during labor
  • Previous birth to a baby with GBS infection
  • Positive test result for GBS in current pregnancy
  • Preterm labor

What are the signs and symptoms of a GBS infection in babies?

GBS infection in babies may be grouped into early-onset and late-onset GBS infection. Early-onset GBS infection occurs within the first week of life, usually within 72 hours of birth. Late-onset GBS infection commonly appears after the first week of birth. Your baby may have any of the following:

  • Eating poorly or vomiting
  • Fast or slow heartbeat and trouble breathing
  • Fever, hypothermia (very low body temperature), or seizures
  • Irritability, drowsiness, or difficulty waking up
  • Sensitivity to bright lights
  • Tense or bulging fontanel (soft spot on the top of his or her head)

How is a GBS infection treated in babies?

Your baby may need to stay in the hospital for treatment. Antibiotic medicines are usually needed to treat GBS infection in babies.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

How can I decrease my baby's risk for a GBS infection?

Screening tests for GBS in mothers may be done during the 35th to 37th weeks of pregnancy. A sample from your vagina or rectum may be taken to check if you carry GBS. If you carry the bacteria, antibiotics will be given during your labor and delivery through an IV. Antibiotics will help prevent you from passing GBS to your baby.

Further information

  • Centers for Disease Control and Prevention (CDC)
    1600 Clifton Road
    Atlanta , GA 30333
    Phone: 1- 800 - 232-4636
    Web Address:

Call your local emergency number (911 in the US) if:

  • Your baby has a seizure.
  • Your baby has trouble breathing and a very fast or slow heartbeat.

When should I call my baby's pediatrician?

  • Your baby is drowsy or more sleepy than usual.
  • Your baby is vomiting often.
  • Your baby's symptoms get worse or return.
  • Your baby has a tense or bulging soft spot on the top of the head.
  • Your baby has a fever.
  • Your baby is eating poorly.
  • Your baby's skin has swelling or a rash.
  • You have questions or concerns about your baby's condition or care.

Care Agreement

You have the right to help plan your child's care. Learn about your child's health condition and how it may be treated. Discuss treatment options with your child's healthcare providers to decide what care you want for your child. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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