Streptococcus pregnancy test

Group B Strep and Pregnancy (for Parents)

What Is Group B Strep?

Group B Streptococcus (group B strep, GBS) is a type of

bacteriaoften found in the urinary tract, digestive system, and reproductive tracts. The bacteria come and go from our bodies, so most people who have it don't know that they do. GBS usually doesn't cause health problems.

What Problems Can Group B Strep Cause?

Health problems from GBS are not common. But it can cause illness in some people, such as the elderly and those with some medical conditions. GBS can cause infections in such areas of the body as the blood, lungs, skin, or bones.

About 1 out of every 4 women have GBS. In pregnant women, GBS can cause infection of the urinary tract, placenta, womb, and amniotic fluid.

Even if they haven't had any symptoms of infection, pregnant women can pass the infection to their babies during labor and delivery.

How Does Group B Strep Affect Babies?

When women with GBS are treated with antibiotics during labor, most of their babies do not have any problems. But some babies can become very sick from GBS. Premature babies are more likely to be infected with GBS than full-term babies because their bodies and immune systems are less developed.

The two types of GBS disease in babies are:

Early-onset infections, which happen during the first week of life. Babies often have symptoms within 24 hours of birth.
Late-onset infections, which develop weeks to months after birth. This type of GBS disease is not well understood.

What Are the Signs & Symptoms of GBS Disease?

Newborns and infants with GBS disease might show these signs:

a fever
feeding problems
breathing problems
irritability or fussiness
inactivity or limpness
trouble keeping a healthy body temperature

Babies with GBS disease can develop serious problems, such as:

pneumonia
sepsis
meningitis (infection of the fluid and lining around the brain). Meningitis is more common with late-onset GBS disease and, in some cases, can lead to hearing loss, vision loss, learning disabilities, seizures, and even death.

How Is Group B Strep Diagnosed?

Pregnant women are routinely tested for GBS late in the pregnancy, usually between weeks 35 and 37. The test is simple, inexpensive, and painless. Called a culture, it involves using a large cotton swab to collect samples from the vagina and rectum. These samples are tested in a lab to check for GBS. The results are usually available in 1 to 3 days.

If a test finds GBS, the woman is said to be "GBS-positive." This means only that she has the bacteria in her body — not that she or her baby will become sick from it.

GBS infection in babies is diagnosed by testing a sample of blood or spinal fluid. But not all babies born to GBS-positive mothers need testing. Most healthy babies are simply watched to see if they have signs of infection.

How Is Group B Strep Treated?

Doctors will test a pregnant woman to see if she has GBS. If she does, she will get intravenous (IV) antibiotics during labor to kill the bacteria. Doctors usually use penicillin, but can give other medicines if a woman is allergic to it.

It's best for a woman to get antibiotics for at least 4 hours before delivery. This simple step greatly helps to prevent the spread of GBS to the baby.

Doctors also might give antibiotics during labor to a pregnant woman if she:

goes into labor prematurely, before being tested for GBS
hasn't been tested for GBS and her water breaks 18 or more hours before delivery
hasn't been tested for GBS and has a fever during labor
had a GBS bladder infection during the pregnancy
had a baby before with GBS disease

Giving antibiotics during labor helps to prevent early-onset GBS disease only. The cause of late-onset disease isn't known, so no method has yet been found to prevent it. Researchers are working to develop a vaccine to prevent GBS infection.

Babies who get GBS disease are treated with antibiotics. These are started as soon as possible to help prevent problems. These babies also may need other treatments, like breathing help and IV fluids.

How Can I Help Prevent Group B Strep Infection?

Because GBS comes and goes from the body, a woman should be tested for it during each pregnancy. Women who are GBS-positive and get antibiotics at the right time during labor do well, and most don't pass the infection to their babies.

If you are GBS-positive and begin to go into labor, go to the hospital rather than laboring at home. By getting IV antibiotics for at least 4 hours before delivery, you can help protect your baby against early-onset GBS disease.

Reviewed by: Thinh Phu Nguyen, MD

Date reviewed: July 2022

Strep B Test: MedlinePlus Medical Test

What is a group B strep test?

Strep B, also known as group B strep (GBS), is a type of bacteria commonly found in the digestive tract, urinary tract, and genital area. It rarely causes symptoms or problems in adults but can be deadly to newborns.

In women, GBS is mostly found in the vagina and rectum. So a pregnant woman who is infected can pass the bacteria to her baby during labor and delivery. GBS can cause pneumonia, meningitis, and other serious illnesses in a baby. GBS infections are the leading cause of death and disability in newborns.

A group B strep test checks for GBS bacteria. If the test shows that a pregnant woman has GBS, she can take antibiotics during labor to protect her baby from infection.

Other names: group B streptococcus, group B beta-hemolytic streptococcus, streptococcus agalactiae, beta-hemolytic strep culture

What is it used for?

A group B strep test is most often used to look for GBS bacteria in pregnant women. Most pregnant women are tested as part of routine prenatal screening. It may also be used to test infants who show signs of infection.

Why do I need a group B strep test?

You may need a strep B test if you are pregnant. The American College of Obstetricians and Gynecologists recommends GBS testing for all pregnant women. Testing is usually done in the 36th or 37th week of pregnancy. If you go into labor earlier than 36 weeks, you may be tested at that time.

A baby may need a group B strep test if he or she has symptoms of infection. These include:

High fever
Trouble with feeding
Trouble breathing
Lack of energy (hard to wake up)

What happens during a group B strep test?

If you are pregnant, your health care provider may order a swab test or a urine test.

For a swab test, you will lie on your back on an exam table. Your health care provider will use a small cotton swab to take a sample of cells and fluids from your vagina and rectum.

For a urine test, you will most likely be told to use the "clean catch method" to ensure your sample is sterile. It includes the following steps.

Wash your hands.
Clean your genital area with a cleansing pad given to you by your provider. To clean, open your labia and wipe from front to back.
Start to urinate into the toilet.
Move the collection container under your urine stream.
Collect at least an ounce or two of urine into the container, which should have markings to indicate the amounts.
Finish urinating into the toilet.
Return the sample container as instructed by your health care provider.

If your baby needs testing, a provider may do a blood test or a spinal tap.

For a blood test, a health care professional will use a small needle to take a blood sample from your baby's heel. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. Your baby may feel a little sting when the needle goes in or out.

A spinal tap, also known as a lumbar puncture, is a test that collects and looks at spinal fluid, the clear liquid that surrounds the brain and spinal cord. During the procedure:

A nurse or other health care provider will hold your baby in a curled-up position.
A health care provider will clean your baby's back and inject an anesthetic into the skin, so your baby won't feel pain during the procedure. The provider may put a numbing cream on your baby's back before this injection.
The provider may also give your baby a sedative and/or pain reliever to help him or her better tolerate the procedure.
Once the area on the back is completely numb, your provider will insert a thin, hollow needle between two vertebrae in the lower spine. Vertebrae are the small backbones that make up the spine.
The provider will withdraw a small amount of cerebrospinal fluid for testing. This will take about five minutes.

Will I need to do anything to prepare for the test?

You don't any special preparations for group B strep tests.

Are there any risks to the test?

There is no risk to you from a swab or urine test. Your baby may have slight pain or bruising after a blood test, but that should go away quickly. Your baby will likely feel some pain after a spinal tap, but that shouldn't last too long. There is also a small risk of infection or bleeding after a spinal tap.

What do the results mean?

If you are pregnant and results show you have GBS bacteria, you will be given antibiotics intravenously (directly to your veins) during labor, at least four hours before delivery. This will prevent you from passing the bacteria to your baby. Taking antibiotics earlier in your pregnancy is not effective, because the bacteria can grow back very quickly. It's also more effective to take antibiotics through your vein, rather than by mouth.

You may not need antibiotics if you are having a planned delivery by Cesarean section (C-section). During a C-section, a baby is delivered through the mother's abdomen rather than vaginally. But you still should be tested during pregnancy because you may go into labor before your scheduled C-section.

If your baby's results show a GBS infection, he or she will be treated with antibiotics. If your provider suspects a GBS infection, he or she may treat your baby before test results are available. This is because GBS can cause serious illness or death.

If you have questions about your results or your baby's results, talk to your health care provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a group B strep test?

Strep B is one type of strep bacteria. Other forms of strep cause different types of infections. These include strep A, which causes strep throat, and streptococcus pneumoniae, which causes the most common type of pneumonia. Streptococcus pneumonia bacteria can also cause infections of the ear, sinuses, and bloodstream.

References

ACOG: The American College of Obstetricians and Gynecologists [Internet]. Washington D.C.: American College of Obstetricians and Gynecologists; c2019. Group B Strep and Pregnancy; 2019 Jul [cited 2019 Nov 15]; [about 3 screens]. Available from: https://www.acog.org/Patients/FAQs/Group-B-Strep-and-Pregnancy
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Group B Strep (GBS): Prevention; [cited 2019 Nov 15]; [about 4 screens]. Available from: https://www.cdc.gov/groupbstrep/about/prevention.html
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Group B Strep (GBS): Signs and Symptoms; [cited 2019 Nov 15]; [about 4 screens]. Available from: https://www.cdc.gov/groupbstrep/about/symptoms.html
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Streptococcus Laboratory: Streptococcus pneumoniae; [cited 2019 Nov 15]; [about 3 screens]. Available from: https://www.cdc.gov/streplab/pneumococcus/index.html
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Travelers' Health: Pneumococcal Disease; [updated 2014 Aug 5; cited 2019 Nov 15]; [about 3 screens]. Available from: https://wwwnc.cdc.gov/travel/diseases/pneumococcal-disease-streptococcus-pneumoniae
Intermountain Healthcare: Primary Children's Hospital [Internet]. Salt Lake City: Intermountain Healthcare; c2019. Lumbar Puncture in a Newborn; [cited 2019 Nov 15]; [about 4 screens]. Available from: https://intermountainhealthcare.org/ext/Dcmnt?ncid=520190573
Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2019. Blood Culture; [updated 2019 Sep 23; cited 2019 Nov 15]; [about 2 screens]. Available from: https://labtestsonline.org/tests/blood-culture
Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2019. Prenatal Group B Strep (GBS) Screening; [updated 2019 May 6; cited 2019 Nov 15]; [about 2 screens]. Available from: https://labtestsonline. org/tests/prenatal-group-b-strep-gbs-screening
Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2019. Urine Culture; [updated 2019 Sep 18; cited 2019 Nov 15]; [about 2 screens]. Available from: https://labtestsonline.org/tests/urine-culture
Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Group B Streptococcal Infections in Newborns[cited 2021 Aug 6]; [about 3 screens]. Available from: https://www.uofmhealth.org/health-library/zp3014spec
University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Group B Streptococcus Infection in Babies; [cited 2019 Nov 15]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=90&contentid=P02363
University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Pneumonia; [cited 2019 Nov 15]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P01321
WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy [Internet]. Geneva (SUI): World Health Organization; c2010. 6. Paediatric and neonatal blood sampling; [cited 2019 Nov 15]; [about 3 screens]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK138647

Culture for group B beta-hemolytic streptococcus (Streptococcus group B, S. agalactiae)

Method of determination The study is carried out by the method of sowing on dense nutrient media. The identification of microorganisms is carried out by mass spectrometry using a Microflex Brucker Daltonik MALDI Biotyper, BRUKER, Germany.

Test material A swab from the entrance to the vagina or anorectal area; vaginal discharge, cervical discharge

Home visit available

Synonyms: Streptococcus group B (S. agalactiae) Culture.

Brief description of the study "Culture for group B beta-hemolytic streptococcus (Streptococcus group B, S. agalactiae)"

Group B streptococcus (GBS, Streptococcus agalactiae) causes severe illness in newborns and is dangerous for certain patients other age groups.

In the vast majority of cases, newborns become infected with GBS during maternal deliveries, with a higher incidence during vaginal delivery. GBS causes early neonatal infections such as sepsis, meningitis, pneumonia, osteomyelitis, arthritis, and pyelonephritis, with rates ranging from 0.2 to 5 or more per 1,000 live births in different countries. In obstetric practice, group B streptococcus is associated with bacteremia, urinary tract infections, chorioamnionitis, premature rupture of amniotic fluid, preterm labor, postpartum endometritis, etc.

GBS in the human body can colonize the oropharynx, anal area of the rectum, vagina (usually vestibule), urogenital tract, skin.

It has been established that GBS in 5-35% of women can be detected in the vagina and often in the urethra of their sexual partners A significant association of carriage of GBS in the vagina has been shown not only with early septicemia of newborns, but also with spontaneous miscarriages, premature birth, premature rupture of amniotic fluid , urinary infection in pregnant women, the birth of children with low body weight, the development of chorioamnionitis in childbirth, endometritis and sepsis in puerperas. The highest level of colonization in women of reproductive age and pregnant women. In pregnant women, GBS is isolated from the listed areas in 7-30% of cases (more often in young people who have high sexual activity or use intrauterine contraceptives). Of these, 60-75% remain GBS carriers until the end of pregnancy.

Vaginal-rectal swabs are collected to detect colonization of the vagina of pregnant women with group B streptococcus. In all other cases, the biomaterial is taken only if there are clinical signs of infection.

GBS has a natural sensitivity to beta-lactam antibiotics, including penicillins. Determination of sensitivity is necessary in cases where the patient has an individual intolerance to drugs of this group.

Isolateable microorganisms and pathogens:

Streptococcus agalactiae.

What is the purpose of culture for group B beta-hemolytic streptococcus (Streptococcus group B, S. agalactiae)? in order to identify bacteriocarrier and determine the need for antibiotic prophylaxis during childbirth, to prevent neonatal complications (septicemia, pneumonia and neonatal meningitis).

What can affect the result of the test "Culture for beta-hemolytic streptococcus group B (Streptococcus group B, S. agalactiae)"

Failure to follow the rules for preparing for the study may affect the result of the test.

Express diagnostics of streptococcus

There are a huge number of pathogenic organisms, and the most common pathogens of infectious diseases are group A streptococci. These are round-shaped microorganisms that cause diseases such as:

pharyngitis
tonsillitis
impetigo
pyoderma
paraproctitis
vaginitis
sepsis
pneumonia
endocarditis
pericarditis
osteomyelitis
purulent arthritis
myositis
phlegmon
omphalitis
scarlet fever
erysipelas
toxic shock syndrome
necrotizing fasciitis
rheumatism
acute glomerulonephritis

Symptoms

The clinical picture of the disease may differ depending on the age of the patient, the affected organ and the presence of concomitant diseases. In a child, the disease manifests itself more rapidly. Chills first, followed by the following symptoms:

nausea and vomiting
green or yellow nasal discharge
decreased appetite
enlarged lymph nodes
sore throat and sore throat
increase in body temperature to high levels.

In adults, streptococcal infections are often very severe. Patients have the same symptoms of the disease that are characteristic of children, but they are more pronounced.

Pregnant women and people with poor health should be especially attentive to their health and protecting the body from streptococcal infection.

Diagnosis

Group A streptococcal infection can be detected in several ways. To determine the pathogen, the following medical studies are carried out.