Ask the Experts
Group B Strep
What is Group B strep?
Your doctor is referring to a test that is routinely given to all women between weeks 35 and 37 of pregnancy. The procedure involves swabbing your vagina and rectum and examining the secretions for the presence of Group B streptococcus (GBS).
GBS is a bacterium that lives in the vagina and intestinal tract of many healthy women without causing symptoms or illness. However, the presence of GBS in the vagina during childbirth poses a risk of serious illness or death to a newborn. Babies most at risk include those whose health is compromised as a result of prematurity; a long, stressful labor; low birth weight; or illness.
About 10 to 30 percent of pregnant women test positive for GBS. If you do, you will be given intravenous antibiotics during labor to limit the risk of transmission to your baby. (If you go into premature labor and have not been screened, you also should receive antibiotics as a precaution.) This type of treatment is highly effective:98 to 99 percent of babies born to women with GBS are not affected by the bacterium.