What Is Group B Strep (GBS) in Pregnancy?

By: Grace Obstetrics & Gynecology in Fort Worth and Granbury, TX

As you get closer to your due date, your provider will talk with you about a routine screening called the Group B strep (GBS) test. If you’ve never heard of it before, or you’ve recently learned that your test was positive, you may have questions.

The good news is that GBS is common, routine to screen for, and very manageable. Understanding what it is and how it’s treated can help you feel more confident as you prepare for labor and delivery.

What Is Group B Strep?

Group B Streptococcus (GBS) is a type of bacteria that naturally lives in the body. Many healthy adults carry it in their digestive tract or genital area without ever knowing it’s there because it usually doesn’t cause symptoms or make you feel sick.

During pregnancy, GBS matters because it can be passed to your baby during labor and delivery. While serious infections in newborns are uncommon, screening helps identify women who would benefit from antibiotics during labor to greatly reduce that risk.

How Common Is GBS?

GBS is much more common than many people realize. About 1 in 4 pregnant women will test positive.

A positive result does not mean you have an infection, that you’ve done anything wrong, or that your pregnancy isn’t healthy. It simply means your provider will take an extra step during labor to help protect your baby.

How Is the Test Done?

GBS screening is typically performed between 36 and 37 weeks of pregnancy.

The test is quick and simple. Your provider will use a swab to collect a sample from the lower vagina and rectum. It usually takes just a few moments, and the sample is sent to a laboratory for testing.

At Grace Obstetrics & Gynecology, this screening is a routine part of prenatal care. Once your results are available, your provider will review them with you and answer any questions you may have.

What Happens If My Test Is Positive?

If your test is positive, there’s no need to panic.

A positive GBS result usually doesn’t require any treatment during pregnancy. Instead, you’ll receive IV antibiotics during labor, most commonly penicillin, to help prevent the bacteria from being passed to your baby during delivery.

This treatment has been used safely for many years and is highly effective at reducing the risk of newborn GBS infection.

What If I’m Allergic to Penicillin?

If you have a penicillin allergy, let your provider know as early as possible. Depending on your allergy history, there are alternative antibiotics that can be used during labor to help protect your baby.

Your provider will discuss the safest option for you well before your due date.

Are There Times Antibiotics Are Recommended Even Without a GBS Test?

In some situations, antibiotics may still be recommended during labor, even if a GBS screening wasn’t completed.

This may happen if:

• You go into labor before your GBS test is performed.
• Your water has been broken for an extended period of time.
• You develop a fever during labor.
• GBS was found in your urine during this pregnancy.
• You’ve previously had a baby with a GBS infection.

Your healthcare team will review your medical history and recommend the safest approach for you and your baby.

What If I’m Having a Planned Cesarean Birth?

If you’re scheduled for a cesarean birth before labor begins and before your water breaks, antibiotics specifically for GBS usually aren’t needed, even if you tested positive.

If labor starts or your water breaks before your scheduled cesarean, your provider will discuss the appropriate next steps.

Can My GBS Status Change?

Yes. GBS can come and go naturally, which is why screening is performed later in pregnancy.

Even if you tested positive in a previous pregnancy, your results may be different this time. That’s why every pregnancy includes its own GBS screening.

Preparing for Delivery with Confidence

For most women, GBS is simply one more routine part of prenatal care. If your test is positive, your labor team will already have a plan in place to help protect your baby, allowing you to focus on welcoming your little one into the world.

At Grace, we believe that understanding your care helps you feel more confident throughout your pregnancy. Whether you’re seeing one of our OB/GYN physicians or one of our certified nurse-midwives, we’re here to answer your questions and guide you every step of the way.

If you have questions about your GBS test or your birth plan, we’d be happy to help. Schedule an appointment at our Fort Worth or Granbury office to speak with a member of our team.