Final answer:
The GBS (Group B Streptococcus) test during pregnancy is typically performed through a vaginal-rectal swab.
Step-by-step explanation:
The GBS (Group B Streptococcus) test during pregnancy is typically performed through a vaginal-rectal swab. A healthcare provider will use a sterile swab to collect samples from the vagina and rectum, which will then be sent to a lab for testing. This test helps to identify if the pregnant woman is carrying GBS bacteria, which can be passed on to the baby during childbirth.