Group B Strep In Pregnancy: Symptoms, Causes And Treatment

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The prevalence of group B strep in pregnancy is common. It is a bacterial species that naturally inhabits pregnant women’s gastrointestinal and reproductive tracts. According to statistics, around 25% of women carry group B strep (GBS) in their vaginal and rectal areas. In most pregnancies, the bacteria may go unnoticed without showing any signs, and it typically does not pose any threat to a pregnant woman’s health. However, under rare circumstances, group B strep may cause infection upon delay in diagnosis and treatment. Thereby affecting the mother’s health during or after pregnancy (postpartum) (1) (2).

This post will help you know more about group B strep in pregnancy, including its causes, symptoms, and treatments.

What Are The Symptoms Of Group B Strep Infection?

The manifestation of the disease varies from person to person depending upon the type of infection caused by the group B strep bacteria.

Newborns or infants who have contracted this bacteria can show the following symptoms (2) (3):

  • High or low body temperature
  • Limpness and minimal body movements
  • Changes in the skin colour
  • Feeding problems
  • Breathing difficulties

Generally, pregnant women giving birth to a GBS-affected baby may not show any bacterial symptoms themselves.

How Does Group B Strep Affect Pregnancy?

In most cases, group B strep might not show any symptoms or pose any threat to a pregnant woman’s health. However, in rare circumstances, it may lead to some morbidities (4) (5) (6).

  • Chorioamnionitis: A breakage in the amniotic sac or a membrane rupture can cause GBS infection in the amniotic fluid and the placental tissues. This will, therefore, lead to chorioamnionitis.
  • Urinary tract infection (UTI): One of the common infections caused by the group B strep bacteria, which can lead to premature birth.
  • Sepsis: Group B strep can cause blood infection in a pregnant woman. It is one of the rarest and most serious infections that could occur during pregnancy from GBS.

How Does Group B Strep Affect A Newborn?

A group B strep-positive mother can transfer the bacteria through the genital tracts during labor and delivery. According to the CDC, the probability of newborns getting GBS-induced disease is one in 4,000 if the mother has received the antibiotics and one in 200 if she has not received antibiotics during delivery or labor (7).

The infections in newborns are divided into two categories (8) (9):

  • Early-onset infections: About 75% of the newborns contract GBS in their first weeks of life, called early-onset disease. The baby may start showing symptoms within the first 24 hours or up to the first seven days following delivery. The infections are sepsis (blood infection), pneumonia (lung infection), and meningitis. Premature babies experience higher risks since they have weaker immune systems. Around 4% to 6% of infant deaths might occur from early-onset GBS infections.
  • Late-onset infections: These are rare where the symptoms may take more than a week or few months to appear. Meningitis is the most observed group B strep infection.

Newborns may have contracted the bacteria from the mother during birth, but late infections can also occur from GBS transfer from another GBS-positive person. However, the exact cause of late infection is still not determined. Late-onset infections hold a lesser probability of infant deaths than early infections.

How Is Group B Strep Diagnosed?

Diagnosis involves a routine screening for GBS between 35 and 37 weeks of pregnancy. Your health care provider will culture the bacteria from rectal and vaginal swabs (4). Upon positive results, the required treatment is administered. Sometimes, urine tests during pregnancy are also carried out to rule out the possibility of UTI caused by GBS (9). Screening for GBS is not routinely recommended to all pregnant women.

How Is Group B Strep Treated?

Antibiotics, mainly penicillin G and ampicillin are the suggested treatment for Group B strep infections and prevent its transfer to the newborn from the mother. These are administered intravenously four hours prior to delivery and throughout labor. Alternatively, vancomycin is administered for those allergic to penicillin (10).

For newborns showing signs of GBS, the doctor will provide a similar IV drip treatment of antibiotics in labor.

Note: In cases of C-section delivery, the affected pregnant women may not require antibiotics treatment unless the labor begins or waters break. It is because the bacteria can only get transferred to the newborn through genital tracts.

How Can You Prevent Group B Strep Infection?

There is no vaccine available for preventing group B streptococcus infections. However, certain preventive measures help minimize the risk of the majority of GBS infections.

    • Testing the pregnant woman to determine the presence of GBS through a vaginal and rectal swab (during 35 to 37 weeks).
    • Administering antibiotics during labor until delivery and not earlier since the bacteria may recolonize the genital tract during labor (11).

In case of negative results and the following conditions, the doctor may consider GBS treatment to prevent further transfer of infection (12):

  • Fever at the time of labor
  • Premature delivery
  • Frequent urination or burning sensation during peeing

Note: Despite the above preventive measures, one may still get GBS. Researchers are working towards finding a definite treatment and vaccination for group B strep.

Can GBS Affect Future Pregnancies?

Yes. If you have been diagnosed with group B strep in your last pregnancy or have given birth to a child with GBS, you may be at a higher risk of developing GBS infection in your future pregnancy. Let your doctor know about your past GBS infections, if any, to avoid complications (12) (8).

Frequently Asked Questions

1. Does strep B go away?

Group B strep is a common bacterium in the body and can naturally go away without causing any symptoms (2). An estimate of a 90% prevention rate is observed with antibiotic treatment (9).

2. Is strep B an STD?

No, group B streptococcus is not a sexually transmitted disease. It is mostly transferred from the mother to the baby during labor or delivery (8).

3. What does group B strep vaginal discharge look like?

While most pregnant women may not have any symptoms, some may notice a white or yellowish vaginal discharge (sometimes accompanied by pus) due to the strep B infection (13).

4. Do I have to stay in the hospital longer if I have group B strep?

It is advised to continue hospital stay for at least 12 hours after childbirth to monitor any additional or progressive symptoms (14). Your doctor may suggest an additional stay, depending on the strep B infection symptoms shown by the baby.

Group B strep infections are a rare occurrence during pregnancy that might be caused due to delays in the diagnosis of the condition. In most cases, the presence of Group B strep does not usually pose a threat to the woman’s or baby’s health. But in some cases, it might give rise to complications such as sepsis, chorioamnionitis, or UTI. Therefore, you must take proper tests to check the presence of strep infections and avoid administering antibiotics until after delivery.

Key Pointers

  • Group B strep may not exhibit any symptoms in pregnant women in most cases; however, some women may experience chorioamnionitis, UTIs, or sepsis.
  • Antibiotic treatment helps avoid vertical transmission.
  • Women with a previous history of group B strep are more susceptible to the infection in subsequent pregnancies.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
  1. Group B strep infection: GBS
  2. Group B strep (GBS)
  3. Group B strep and pregnancy
  4. Group B streptococcus.
  5. GBS in pregnancy and newborn.
  6. What are the risks of group b streptococcus infection during pregnancy
  7. Group B strep fast facts.
  8. Group B strep and pregnancy.
  9. Group B streptococcus & pregnancy.–pregnancy
  10. John A. Morgan et. al. (2021). Group B streptococcus and pregnancy.
  11. Group B streptococcus symptoms and causes.
  12. Group B streptococcus infections in babies.
  13. E. Honig et al. Can Group B Streptococci Cause Symptomatic Vaginitis?
  14. Group B strep.
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Aneesha Amonz

Aneesha holds a Bachelor's degree in Biotechnology from USTM, Meghalaya and Master’s degree in Applied Microbiology from VIT, Vellore. She has worked on different research projects in the field of Food Sciences. In addition, she has an internship experience in Oil India Limited as an R&D project trainee. As a writer at MomJunction, Aneesha ensures her content is engaging and... more

Dr. Shweta Shah

Dr Shweta is a passionate and skilled gynaecologist with unparalleled experience in her field of around a decade . She herself being a woman , connects and resonates with her patients like her beloved family. She is a prolific doctor who can be related to women across all walks of life. Compassionate and warm, Dr. Shweta Shah is a patient-centric... more