Medical Conditions

Group B Strep (GBS) Infection in Newborns

Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist

Content reviewed against published AAP, CDC guidelines

Last reviewed: June 2026

If your baby has been diagnosed with or you suspect group b strep (gbs) infection in newborns, here is what the evidence says.

The short answer

Key takeaways

Group B Streptococcus (GBS) is a bacterium that some mothers carry and can pass to their baby during delivery. When mothers who test positive receive antibiotics during labor, the risk to the baby is greatly reduced. GBS infection in newborns can be serious, causing sepsis, pneumonia, or meningitis, but with prevention measures and prompt treatment, most babies do well.
Usually normal when: Mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth
Call your doctor if: Any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete
Varies by age — see the age-by-age breakdown below

“Fever itself is not an illness — rather, it is a sign or symptom that the body is fighting an infection. Fever stimulates certain defenses, such as the white blood cells, which attack and destroy invading bacteria.”

— Fever and Your Child, American Academy of Pediatrics (AAP)

Parents everywhere have the same worry. You are doing the right thing by looking into it.

What Parents Should Know

According to AAP, CDC guidelines, group B Streptococcus (GBS) is a bacterium that some mothers carry and can pass to their baby during delivery. When mothers who test positive receive antibiotics during labor, the risk to the baby is greatly reduced. GBS infection in newborns can be serious, causing sepsis, pneumonia, or meningitis, but with prevention measures and prompt treatment, most babies do well. At 0-1 month, early-onset GBS disease occurs within the first week of life (usually within 24-48 hours) and is acquired during passage through the birth canal. Prevention through maternal antibiotic treatment during labor has dramatically reduced early-onset GBS disease. If your baby was born to a GBS-positive mother who received adequate antibiotics during labor, the risk is very low. Babies born to GBS-positive mothers who did not receive adequate antibiotics, or who show any signs of illness, are monitored closely and may receive empiric antibiotics. Late-onset GBS disease (1 week to 3 months) can occur from maternal or environmental sources. It is generally considered normal when mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth. However, you should contact your pediatrician promptly if any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete.

Sources: [1], [2]

Normal vs. Concerning

Usually Normal

Worth Discussing

Mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth

Any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete

Baby was observed for the recommended period after birth and showed no signs of infection

Signs of infection at any point in the first 3 months of life

Baby is feeding well, maintaining normal temperature, and is alert and active

You were GBS positive and are unsure if you received adequate antibiotics during labor

By Age

What to expect by age

0-1 month

Early-onset GBS disease occurs within the first week of life (usually within 24-48 hours) and is acquired during passage through the birth canal. Prevention through maternal antibiotic treatment during labor has dramatically reduced early-onset GBS disease. If your baby was born to a GBS-positive mother who received adequate antibiotics during labor, the risk is very low. Babies born to GBS-positive mothers who did not receive adequate antibiotics, or who show any signs of illness, are monitored closely and may receive empiric antibiotics. Late-onset GBS disease (1 week to 3 months) can occur from maternal or environmental sources.

1-3 months

Late-onset GBS disease can occur during this period. Signs include fever, irritability, poor feeding, and lethargy. Late-onset GBS can cause meningitis, bloodstream infection, or bone/joint infection. Any fever in a baby under 3 months requires emergency evaluation, which includes testing for GBS among other bacterial causes.

3-6 months

GBS infection becomes very rare after 3 months of age. Babies who had GBS infections that were treated promptly typically recover fully. Those who had GBS meningitis may need developmental follow-up.

6-12 months

GBS infection risk is negligible at this age. Babies who recovered from GBS infection in the newborn period should have normal development, though those who had meningitis may need monitoring for hearing and developmental milestones.

What to Tell Your Pediatrician

Describe when you first noticed group b strep (gbs) infection in newborns and how it has changed over time.
Note your baby's current age and which age-specific patterns you are seeing.
Mention if you were GBS positive and are unsure if you received adequate antibiotics during labor.
Mention if your baby seems slightly unwell in the first few days after birth.
Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...

Mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth
Baby was observed for the recommended period after birth and showed no signs of infection
Baby is feeding well, maintaining normal temperature, and is alert and active

Mention at your next visit when...

You were GBS positive and are unsure if you received adequate antibiotics during labor
Your baby seems slightly unwell in the first few days after birth
You have questions about GBS prevention for future pregnancies

Act now when...

Any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete
Signs of infection at any point in the first 3 months of life

What You Can Do at Home

Keep track of when you notice group b strep (gbs) infection in newborns — noting the time of day, duration, and any triggers can help your pediatrician.
Remember that mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth — this is generally within the range of normal.
At 0-1 month, focus on observation rather than intervention unless your pediatrician advises otherwise.
Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
While monitoring at home, seek immediate care if any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete.

Signs of Infection and Sepsis in Newborns

Neonatal sepsis is a serious bacterial infection in the bloodstream that can develop in the first month of life. Signs are often subtle and can include temperature instability, poor feeding, lethargy, irritability, rapid breathing, and a "just not right" appearance. Neonatal sepsis is a medical emergency requiring immediate antibiotics. Trust your instincts if your newborn seems unwell.

Fever in a Baby Under 3 Months Old

A fever in a baby under 3 months old (temperature of 100.4 degrees F / 38 degrees C or higher taken rectally) is always a medical emergency. Go to the emergency room immediately, regardless of how well your baby appears. Young babies' immune systems cannot fight infections as effectively as older children, and a fever could indicate a serious bacterial infection (urinary tract infection, bacteremia, or meningitis) that needs urgent treatment. Do NOT wait to see if the fever goes down. Do NOT give fever medication and stay home - go to the ER first.

Milestone

Month-by-Month Development

Detailed monthly development guides from birth through 24 months.

Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is group b strep (gbs) infection in newborns normal?

When should I call the doctor about group b strep (gbs) infection in newborns?

Any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete Signs of infection at any point in the first 3 months of life

When is group b strep (gbs) infection in newborns normal?

Mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth Baby was observed for the recommended period after birth and showed no signs of infection Baby is feeding well, maintaining normal temperature, and is alert and active

What causes group b strep (gbs) infection in newborns?

Group B Streptococcus (GBS) is a bacterium that some mothers carry and can pass to their baby during delivery. When mothers who test positive receive antibiotics during labor, the risk to the baby is greatly reduced. GBS infection in newborns can be serious, causing sepsis, pneumonia, or meningitis, but with prevention measures and prompt treatment, most babies do well. Common explanations include: Mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth. Baby was observed for the recommended period after birth and showed no signs of infection.

What should I mention to my pediatrician about group b strep (gbs) infection in newborns?

You should mention group b strep (gbs) infection in newborns at your next visit if: You were GBS positive and are unsure if you received adequate antibiotics during labor. Your baby seems slightly unwell in the first few days after birth. You have questions about GBS prevention for future pregnancies.

Is group b strep (gbs) infection in newborns normal at 0-1 month?

Is group b strep (gbs) infection in newborns normal at 1-3 months?

Should I go to the ER for group b strep (gbs) infection in newborns?

Seek emergency care if any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete, or if signs of infection at any point in the first 3 months of life. When in doubt, call your pediatrician's after-hours line for guidance.

Does group b strep (gbs) infection in newborns go away on its own?

In many cases, group b strep (gbs) infection in newborns resolves on its own, especially when mother was GBS positive, received adequate antibiotics during labor, and baby has been well since birth. By 6-12 months, gBS infection risk is negligible at this age. Babies who recovered from GBS infection in the newborn period should have normal development, though those who had meningitis may need monitoring for hearing and developmental milestones.

AAP CDC

References

[1]American Academy of Pediatrics. Prevention of Group B Streptococcal Disease in Newborns. Pediatrics. AAP
[2]Centers for Disease Control and Prevention. Group B Strep Prevention. CDC

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Group B Strep (GBS) Infection in Newborns.

Things to mention

Describe when you first noticed group b strep (gbs) infection in newborns and how it has changed over time.
Note your baby's current age and which age-specific patterns you are seeing.
Mention if you were GBS positive and are unsure if you received adequate antibiotics during labor.
Mention if your baby seems slightly unwell in the first few days after birth.
Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

You were GBS positive and are unsure if you received adequate antibiotics during labor
Your baby seems slightly unwell in the first few days after birth
You have questions about GBS prevention for future pregnancies

Urgent signs to report immediately

Any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a GBS-positive mother or if maternal antibiotic treatment was incomplete
Signs of infection at any point in the first 3 months of life

My notes

From ismybabyalright.com — free, evidence-based baby health guides

All content follows our editorial policy and is reviewed against published clinical guidelines.

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Bottom line

Most cases of group b strep (gbs) infection in newborns are normal. Talk to your pediatrician if any fever, poor feeding, lethargy, rapid breathing, or unusual irritability in a newborn, especially if born to a gbs-positive mother or if maternal antibiotic treatment was incomplete.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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