Patient information from BMJ

Group B strep infection in newborns

Last published:Aug 13, 2020

Sometimes newborn babies become infected with bacteria (germs) called group B streptococcus. The bacteria are passed on from a mother to her baby during birth. This infection can be serious and needs to be treated quickly. Women are sometimes given antibiotics during labor to prevent this infection.

We've looked at the best and most up-to-date research to produce this information. You can use it to talk to your doctor and decide which treatments are right for you and your baby.

What is it?

Infection with group B streptococcus is quite rare but serious, as it can make a newborn baby very ill.

Group B streptococcus is also called group B strep or GBS. Group B strep can live in your body without causing any problems. But if these bacteria spread from a mother to her baby during birth, they can cause serious illnesses, including infections of the blood (sepsis), in the lungs (pneumonia), in the urinary tract, and around the brain (meningitis).

There are two main types of group B strep infection in babies.

If a baby gets group B strep infection in the first six days of life, it's called early-onset infection. Doctors think this happens when babies breathe in fluid that contains group B strep during labor.

If a baby gets group B strep infection from seven days to three months after birth, it's called late-onset infection. Doctors aren't certain how this infection happens.

This information is about preventing and treating early-onset group B strep infections.

Some things make it more likely that your baby will get early-onset group B strep infection. These are called risk factors. If you have a risk factor, it doesn't mean your baby will get the infection. But it does mean your baby's chance of getting the infection is higher.

Your baby is more likely to get early-onset group B strep infection if:

• You carry group B strep bacteria in your body

• You've had a baby with a group B strep infection before

• Your baby is born before the 37th week of pregnancy

• You have a fever when you are in labor

• Your water breaks early.

What are the symptoms?

Most babies who get early-onset group B strep infections become ill within the first few hours of their life.

Some signs and symptoms of early infection in newborn babies are:

• Rapid breathing or difficulty breathing (often the first symptom)

• Grunting

• A high temperature (fever), or a low temperature

• Difficulty feeding or not wanting to feed

• Being floppy, limp, and hard to wake up.

It's very important that you get medical help right away if you think that your baby is ill. Group B strep infection is serious, and your baby may become very ill very quickly.

Preventing group B strep infections in newborn babies

In the United States, all pregnant women are tested between the 35th and 37th week of pregnancy to see if they have group B strep.

Your doctor will use a small swab to take a sample of cells from your vagina and rectum. If your test shows that you're carrying group B strep, you'll be given antibiotics during labor through a drip into a vein (an intravenous infusion, or IV). Antibiotics are drugs that kill bacteria. The aim of this treatment is to prevent group B strep from passing from you to your baby.

Babies at most risk of getting a group B strep infection may be given antibiotics when they are born, to try to prevent the infection. But doctors don't always agree about whether all babies who are at risk should be given antibiotic treatment. If your baby is well and has no signs of an infection, they will probably not need treatment.

Treating group B strep in newborn babies

If your baby is unwell, you should get medical help right away. Babies who have group B strep infection need to be treated quickly with antibiotics.

Antibiotics cure the infection in most babies. They are given to your baby through a drip (an IV). They can cause side effects, but these are usually mild, such as diarrhea or a rash.

What will happen to my baby?

Newborn babies who get group B strep infection need to be treated as soon as possible. Most babies who are treated early make a full recovery. But a few babies die. Also, some babies who get a group B strep infection of the fluid and lining around the brain (meningitis) will have permanent nerve damage. They may get problems with their hearing or sight, or seizures. About half of babies who get meningitis from a group B strep infection go on to have long-term problems.