Focus on Women

Pregnancy alert: A test you don’t want to miss

When you’re pregnant, you get used to being tested. A lot.

There’s the usual office-visit urine test, blood tests, occasional vaginal exam and—the pretty gross but necessary—glucose test.

Among this array of exams, one test that many pregnant women don’t give a second thought to is the Group B strep test, usually conducted when you’re 35 to 36 weeks pregnant. A simple vaginal swab, the group B strep test checks your birth canal for presence of group B streptococcal bacteria, which is fairly common.

“About one-fourth of women at any given time will have Group B strep bacteria,” said Dr. Linda Street, an OBGYN at Augusta University Women’s Health.

Most of the time, the bacteria isn’t harmful at all, happy to cohabitate with us as we go about our day-to-day lives, but for some babies, its presence can be catastrophic. As babies with their immature immune systems pass through the birth canal, they can be exposed to the virus, which can cause meningitis (infection of the fluid and lining around the brain), sepsis (blood infection), pneumonia and even death. Babies who survive can also develop cerebral palsy and other lifelong disabilities as a result of the infection.

Babies of mothers who test positive for group B strep have a 1 in 200 chance of contracting an infection. But the good news is that risk drops to 1 in 4,000 with just one simple treatment: IV antibiotics.

Test positive? Here’s what you need to do

Once you start labor, it’s go time in more ways than one.

“IV antibiotics during labor is the only treatment for group B strep,” Street said. “In other words, you can’t take antibiotics ahead of time.”

If you tested positive, ask your physician or midwife how far apart contractions need to be before you head to the hospital; however, in most cases, you should go right away, especially if labor pains come early (say at 37 weeks) or if your water has broken, since prematurity and membrane rupture both increase risk of infection in newborns.

As soon as you arrive at the hospital and labor is confirmed, your medical team will place you on IV antibiotics, typically penicillin, or an alternate if you are allergic to penicillin. The dose will be repeated every four hours until your baby is born, with a goal for you to receive at least two doses during labor.

Births have a way of not going to plan, so if your labor is fast and you’re not able to get antibiotics or were able to get only one dose, don’t worry. Your hospital will closely monitor your baby for at least 48 hours, including blood testing and possible antibiotics to help treat any sign of infection. If your child does test positive or shows symptoms of group B strep infection, he or she will likely be treated at the hospital with IV antibiotics for about a week.

If your doctor has advised you to have a caesarean section, one bonus is that you shouldn’t have to worry about group B strep, even if you tested positive (so long as your water doesn’t break before your scheduled delivery).

“Since babies don’t pass through the birth canal with C-section, there’s very little concern about contracting group B strep,” Street said.

Moms should also know that for most full-term, healthy babies, group B strep isn’t a concern, even with a positive test.

“As long as you’re getting routine prenatal care, your doctor is going to worry about group B strep for you,” Street said. “However, it’s important that women are aware of the importance of this test and treatment since infection is so easily preventable just through routine care.”

Need an OBGYN?

Our specialists are trusted with the most complex cases—so why not trust us with the routine, too? To find a doctor or schedule an appointment at Augusta University Women’s Health, visit, or call 706-721-4959.

About the author

Augusta University Health

Based in Augusta, Georgia, Augusta University Health is a world-class health care network, offering the most comprehensive primary, specialty and subspecialty care in the region. Augusta University Health provides skilled, compassionate care to its patients, conducts leading-edge clinical research and fosters the medical education and training of tomorrow’s health care practitioners. Augusta University Health is a not-for-profit corporation that manages the clinical operations associated with Augusta University.