If Your Baby Has Group B Strep

Medically Reviewed by Renee A. Alli, MD on July 08, 2023
4 min read

Group B strep is a bacterial infection babies can catch from their mother during childbirth or pick up in their first few months of life. Infants who get this infection can have complications like pneumonia, meningitis, or a blood infection called sepsis.

This infection is preventable. If you're pregnant and tests show that you have this type of bacteria, your doctor can give you antibiotics during labor so you don't pass the infection to your baby. And if your baby does get sick, antibiotics can treat the infection.

Group B strep bacteria live in the intestines and genital tract, including the vagina. About 1 out of every 4 pregnant women carries these bacteria.

It's normal to have these bacteria in your body. Usually you won't know you have them because they won't make you sick. In some cases, they can cause bladder and urinary tract infections (UTIs). Group strep B bacteria aren’t dangerous to you, but if you get pregnant, they are risky for your baby.

If you carry group B strep bacteria, your baby can become infected during a vaginal delivery. Not every baby who is exposed to GBS will get infected, but a small percentage can

It’s more likely if:

  • You deliver early -- before 37 weeks
  • Your water breaks 18 hours or more before you deliver
  • You have an infection of the amniotic fluid or placenta
  • You've had a baby with GBS in the past
  • You have a fever higher than 100.4 F during labor

Babies can get two types of GBS infection: Early-onset starts during a newborn's first week of life. Babies get this type during delivery. Late-onset starts a week to a few months after the baby is born. This type may be acquired in the home or in the community, and it isn't prevented by antibiotics given during delivery. 

Babies who get this infection may start to have symptoms in the first few days of life, or weeks to months later. You may notice that your little one has:

  • Fever
  • Fast, slow, or strained breathing
  • Trouble eating
  • Extreme fatigue
  • Irritability
  • Blue color to the skin

Babies with group B strep bacteria could get serious complications like these:

  • Pneumonia -- a lung infection
  • Meningitis -- inflammation in the lining of the brain and spinal cord
  • Sepsis -- a blood infection

These conditions can be life-threatening. They can also lead to long-term problems such as:

 

Your OB/GYN might do a urine culture early in your pregnancy to look for group B strep bacteria. You should be tested for it between your 35th and 37th weeks of pregnancy. The doctor will take a swab from your vagina and rectum and send it to a lab. A “positive” result means you carry this type of bacteria.

If your newborn shows symptoms of this infection after birth, the doctor can take a sample of the baby's blood or spinal fluid and send it to a lab. The lab will culture the bacteria to see if group B strep bacteria grow. This process can take a few days. A chest X-ray may also help doctors diagnose the infection in babies.

Even before lab results are in, intravenous antibiotic treatment may be started. 

Your baby might also need treatments to help with GBS symptoms, including:

  • Fluids through a vein (IV)
  • Oxygen
  • Medicines to treat other symptoms

 

Researchers are working on a vaccine that might one day protect mothers and their babies from this infection. But it’s not ready yet.

If tests show that you have group B strep bacteria while pregnant, your doctor will give you antibiotics during labor to prevent you from passing the infection to your baby.

Penicillin and ampicillin are two antibiotics commonly used to treat this infection. If you're allergic to penicillin, your doctor can give you a different drug.

You need to take antibiotics during labor, not before. If you take them earlier in your pregnancy, the bacteria can come back.

You won't need to take antibiotics if you have a C-section before your water breaks.

Taking antibiotics during labor will prevent early-onset group B strep infections in your baby. But it won’t lower the odds that your baby will develop the late-onset form. So keep note of any possible symptoms in your baby, particularly in the first three months of life.