Group B Streptococcal Infections in Newborns

Condition Basics

What is group B streptococcal infection?

Group B streptococcus (strep) is a serious bacterial infection. If you carry group B streptococcal bacteria, you may have the bacteria but have no infection from it. But newborns may have the infection hours after delivery. Or it can develop during the first few weeks after birth.

What causes it?

Group B strep bacteria normally exist in the intestine, vagina, or rectum. If you carry group B streptococcal bacteria, you may have the bacteria but have no infection from it. But your baby could get the infection during birth. It is unclear why some babies get group B strep infection and others do not.

Newborns may develop the infection hours after birth or during the first week of life, or it may happen several months later. It's not clear how babies who develop the infection later are exposed to the bacteria.

What are the symptoms?

Symptoms of group B strep may include high or low body temperature, irritability, low energy, raised breathing rate, and trouble feeding. Newborns also may get infections of the blood (sepsis), lung (pneumonia), or tissues around the brain and spinal cord (meningitis). Newborns infected with group B strep need medical care right away.

How is it diagnosed?

Tests for group B strep are done in the third trimester of pregnancy. Babies suspected of being infected are diagnosed at birth by testing their blood or urine or both for the bacteria. Babies may get a chest X-ray. If they show signs of a serious infection, the doctor may test the spinal fluid.

How is group B streptococcal infection treated?

If you have group B strep infection or carry group B strep, you will get antibiotics before delivery. This will prevent giving the bacteria to your baby during delivery. If you're pregnant and gave birth before to a child with group B strep infection, you should be treated with antibiotics. You should also be treated if you've had tests that show you carry the bacteria.

Newborns with the infection will also be given antibiotics. In addition to antibiotics, supportive care including fluids and ventilation will be given if needed. In some cases, a doctor will treat a newborn that is suspected of having group B strep infection before test results have shown infection. This is because not treating strep B infection in newborns can result in illness or death.


Current as of: June 12, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.