Beta Strep during Pregnancy

What is group B streptococcus (beta strep)?

Group B streptococcus (also called beta strep, or GBS), is a very common type of bacteria. Ten to thirty percent of pregnant women carry GBS bacteria. Most often the bacteria are in the vagina or rectum. GBS bacteria are different from the type of bacteria that cause strep throat.

Healthy adults carrying GBS usually do not have any symptoms or problems that would suggest an active infection and no treatment is needed. However, sometimes the bacteria can cause an infection in the uterus, bladder, kidneys, or, rarely, the brain (meningitis). Although these infections in adults are usually not serious, most will need to be treated with antibiotics. If a mother is carrying the bacteria, the baby may develop an active infection during the labor and delivery process. In that situation, the baby may get very sick and possibly die if not treated with the proper medicines.

How does it occur?

Both women and men may have GBS. The bacteria often live in the mouth, bowel, bladder, vagina, and rectum. A woman who carries GBS can pass it to her baby during labor or delivery.

What are the symptoms?

In most cases pregnant women do not have any symptoms of infection. When they do have symptoms, they may include:

• fever over 100°F during labor
• painful, bloody, frequent, or urgent urination

How is it diagnosed?

GBS can be found by testing urine or swabbing the cervix, vagina, or rectum. The samples of fluid are cultured in a lab. A test result is positive if beta strep bacteria are found in the culture. The test is negative if the bacteria are not found. The Centers for Disease Control (CDC) recommends that all pregnant women have a GBS culture in the 35th to 37th weeks of pregnancy. A culture may also be done if you have premature rupture of the membranes, a fever during labor, or urinary tract symptoms such as painful, bloody, or frequent urination.

A rapid test for GBS may be done when you go to the hospital to deliver your baby. The results of this test can be known in 2 to 3 hours. However, it is less accurate than cultures and is rarely used earlier in a pregnancy.

How is it treated?

If your tests for beta strep are positive and you have no symptoms, you will probably not be treated until you are in labor. During labor you will be given intravenous (IV) antibiotics. However, if a urine culture, done at any time during pregnancy, shows that GBS is causing a bladder infection, your healthcare provider will probably prescribe an oral antibiotic to treat the infection.

Because infection of the baby can cause serious problems, you may be treated with antibiotics during labor if you have any risk factors for beta strep infection, even if your test results are negative. The risk factors are:

• preterm labor (labor that starts before 37 weeks of pregnancy)
• premature rupture of membranes (water breaking before 37 weeks of pregnancy)
• membranes ruptured for longer than 18 hours
• a previous child with beta strep infection
• fever (higher than 100.4°F, or 38.0°C) during labor
• GBS bacteria found sometime during the pregnancy

Treatment with IV antibiotics during labor is usually very effective. Babies rarely develop the serious side effects of GBS infection with this treatment.

If a newborn develops any signs or symptoms of GBS infection, the baby is treated with IV antibiotics and watched very closely. The baby may stay in a special intensive care unit.

How long will the effects last?

A woman who has GBS does not usually have any symptoms of illness or long-lasting effects. The main risk is that the newborn will become sick. GBS infection can affect the baby's blood, brain, spinal cord, or lungs. The baby may have long-term problems that affect hearing, vision, or learning abilities if the brain is infected. For the most serious infections, the baby might die.

How can I help prevent GBS infection of the baby?

Getting tested for GBS and being treated with antibiotics during labor, if necessary, greatly reduces the risk that your baby will be infected with GBS.

Written by Edward Zabrek, MD.
Published by RelayHealth.
© 2009 RelayHealth and/or its affiliates. All Rights Reserved.