Group B strep

Mayo Clinic Health Manager

Get free personalized health guidance for you and your family.

Get Started

Free

E-Newsletter

Subscribe to receive the latest updates on health topics. About our newsletters

  • Housecall
  • Alzheimer's caregiving
  • Living with cancer

Tests and diagnosis

By Mayo Clinic staff

If you're pregnant, the Centers for Disease Control and Prevention recommends a group B strep screening between weeks 35 and 37 of pregnancy. Your doctor will take a swab sample from your vagina and rectum and send it to a lab for testing. A positive test indicates that you carry group B strep. It doesn't mean that you're ill or that your baby will be affected. It simply means the potential for newborn infection exists, and you can take steps to protect your baby.

If you've already given birth, and your doctor suspects your baby has group B strep disease, a sample of your baby's blood or spinal fluid will be sent to a lab for evaluation.

Group B strep infection and group B strep disease are diagnosed when the bacteria are grown from cultures of the fluid samples. The cultures take several days to grow, so it may be two to three days before you receive the results of the lab analysis.

References
  1. Repke JT, et al. Patient information: Group B streptococcus and pregnancy. http://www.uptodate.com/home/index.html. Accessed Aug. 12, 2008.
  2. Group B strep prevention: Frequently asked questions. Centers for Disease Control and Prevention. http://www.cdc.gov/GroupBStrep/general/gen_public_faq.htm. Accessed Sept. 2, 2008.
  3. Group B strep prevention: Beyond newborns and mothers - some facts about group B strep disease in the rest of the population. Centers for Disease Control and Prevention. http://www.cdc.gov/groupbstrep/general/gen_public_adult.htm. Accessed Sept. 2, 2008.
  4. Group B strep prevention: Protect your baby from group B strep! Centers for Disease Control and Prevention. http://www.cdc.gov/groupbstrep/general/protect-your-baby-GBS.htm. Accessed Sept. 2, 2008.
  5. Puopolo KM, et al. Group B streptococcal infection in pregnant women. http://www.uptodate.com/home/index.html. Accessed Aug. 12, 2008.
  6. Urinary tract infections in women. American Academy of Family Physicians. http://familydoctor.org/online/famdocen/home/women/gen-health/190.html.  Accessed Sept. 16, 2008.
  7. Puopolo KM, et al. Group B streptococcal infection in neonates and young infants. http://www.uptodate.com/home/index.html. Accessed Aug. 12, 2008.
  8. Baron M, et al. Group B streptococcal infection in nonpregnant adults. http://www.uptodate.com/home/index.html. Accessed Aug. 12, 2008.

DS01107

Dec. 5, 2008

© 1998-2009 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Reliable tools for healthier lives," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

Print Share Reprints

Text Size: smaller largerlarger