GBS screening and late-pregnancy tests: what to expect near the end

As birth gets closer, visits become more frequent and some tests are repeated. One of the most asked-about is GBS screening. It is a simple swab, and knowing the result makes it easier to protect your baby during birth.

What is GBS?

Group B Streptococcus (GBS) is a bacterium that many healthy adults carry harmlessly in the gut or vagina. Most carriers have no symptoms. It is not a sign of illness and has nothing to do with hygiene.

Rarely, it can pass to the baby during birth and cause an infection in the newborn. That is why it helps to know whether you carry it. Most babies never have a problem with this bacterium; the aim is simply to lower the chance further. Knowing your result helps your birth plan go ahead calmly and with good information.

When and how is the screening done?

Screening is usually done in the last weeks of pregnancy. It is not part of the Turkish Ministry of Health guideline; international guidelines (such as ACOG) generally recommend it around weeks 36–37. Practice varies by country and doctor, and your doctor decides whether and when it is done.

The test is painless. A cotton swab is taken from the lower vagina and the rectum, which takes a few seconds. Results usually come back within a few days.

If the result is positive

Being GBS positive does not mean your baby will be infected. Most babies of carriers are born healthy. Your doctor will usually suggest antibiotics through a drip during labour, which helps reduce the chance of the bacteria passing to the baby considerably.

When you arrive for birth, just tell the team you are GBS positive. Carrier status can change between pregnancies, so it is checked again each time.

Other late-pregnancy tests

Depending on your situation, your doctor may suggest:

• Blood count: A check for anaemia, which matters in preparing for birth.
• Urine test: To look for urinary infection and protein.
• Antibody check if you are Rh negative: Repeated if planned earlier.
• Blood pressure and swelling check: Done at every visit.
• Your baby's growth and position: Assessed by examination and, if needed, ultrasound.

This list is not the same for everyone. Your doctor decides which tests are needed.

What you can do

• If the doctor or lab gives special instructions before the swab, follow them; you are usually asked not to use vaginal products beforehand.
• Get a written copy of your result and put it in your hospital bag.
• Note your GBS status in your birth plan.
• Ask about signs of labour and when to go to the hospital at the fourth visit.
• You can log contractions with the contraction timer in the app.

When to contact your doctor

• If you have regular, closer-together contractions or your waters break
• If you have vaginal bleeding
• If you have a temperature of 38 °C or higher
• If your baby's movements clearly decrease
• If you notice a severe headache, blurred vision or sudden swelling

In an emergency call 112 (or your local emergency number). This article is for information; your doctor's advice for your own situation comes first.