Group B strep test in pregnancy: what to expect

Group B streptococcus (GBS) is a bacterium that about 25% of healthy adults carry naturally in the gut and vaginal tract without any symptoms or health effects. In newborns, however, it can cause serious infection. This is why all pregnant women are routinely tested between weeks 35–37 with a simple vaginal and rectal swab.

If you test positive, it doesn't mean you're sick — it simply means you'll receive IV antibiotics during labor to prevent the bacteria from being passed to your baby during delivery. The test itself takes less than a minute and results are available within a few days. A positive result requires no treatment before labor and doesn't affect your birth plan in any other way.