Group B strep swab in pregnancy
group B strep test · GBS swab · Streptococcus agalactiae · swab before birth · GBS culture
This is a swab from the vagina and rectum. It looks for a germ that is usually harmless to the mother but can harm the baby during birth.
It is usually offered to all pregnant women near the end of pregnancy, about a month before the due date.
⏱ Duration: the swab takes about a minute; results usually come in 2 to 4 days
Be sure to tell your doctor
How to prepare
- Timing. The swab is usually taken at 36 to 37 weeks. Your doctor will set the exact time.
- Hygiene. The day before, do not wash inside the vagina or use suppositories, unless your doctor prescribed them. Ask your doctor.
- Medicines. Do not stop prescribed medicines on your own. Tell your doctor about all your medicines.
What to bring
- Your pregnancy record card
- Your referral
- Your ID
How it goes
- You lie on the gynecology exam chair
- The doctor runs a swab around the opening of the vagina
- Then, with the same or another swab, gently just inside the opening of the rectum
- The swab is put in a tube
- Sometimes you can take the swab yourself, following the doctor's instructions
What you'll feel
- A little unpleasant, but not painful
- It lasts a few seconds
Afterwards
- You can go back to your usual day right away
- If the germ is found, you will get an antibiotic through a drip during labor. This protects the baby
- Tell the maternity hospital about your result
Contact a doctor straight away if
- Your waters are leaking or contractions have started: go to the maternity hospital or call emergency services
- Bleeding: call emergency services
- A fever, or the baby is moving less: go to the maternity hospital urgently
Common questions
If strep B is found, is it dangerous for me?
Usually not. Many healthy women carry it. The main thing is to protect the baby during birth.
Should strep B be treated before birth?
Usually not. It can come back. The key is the antibiotic during labor.