Why should I be tested for group B streptococcus during pregnancy?

Group B strep is a bacterium that about 20 to 30 percent of moms carry and that a baby can catch on the way out and get very sick. Because of this, the recommendation is that all moms receive a group B strep culture between 35 and 37 weeks gestation. If it comes back positive, then a mom will receive antibiotics during her labor process. If it is negative, she does not need the antibiotics.

Studies show that about 20% of pregnant women carry the group B streptococcus (GBS) bacteria but have no symptoms. For this reason, it's recommended that all pregnant women be tested for GBS late in pregnancy, usually in the last 5 weeks of pregnancy. Testing during pregnancy is the only way to detect this common bacteria so that your doctor can plan steps to help protect your baby.

Testing is quick and painless. Your doctor will swab your vagina and rectum and send the sample to the lab. There the sample will be cultured (grown in a special substance). GBS swab test results are usually available within 48 hours. A positive test result means that GBS is present.