The Group B Strep (GBS) test is a routine screening performed in your third trimester to check for the presence of a common bacteria that can be passed to your baby during birth. This test, sometimes called a GBS swab or strep B test, is a universal standard of care in countries like the US, UK, and Canada, reflecting a collaborative effort to support neonatal health.
As a birth doula, I often see how understanding these routine screenings can bring a sense of calm and clarity as you approach your birthing time. Just as an early Dating Ultrasound provides a first glimpse into your pregnancy, and the First Prenatal Blood Panel offers foundational health insights, the GBS test is another piece of the puzzle, designed to give you and your care team information to make informed decisions.
What it is
Group B Strep is a common type of bacteria that can live in the intestines and lower genital tract. It's important to understand that GBS colonization is not a sexually transmitted infection, nor does it typically cause symptoms or illness in pregnant people. In fact, it's quite common, colonizing about 20–30% of pregnant individuals without them ever knowing it. The purpose of the screening is not to treat you for an infection, but to identify if the bacteria is present, as it could potentially pass to your baby during a vaginal birth.
While universal screening is the prevailing approach in many regions, it's worth noting that some European centers, particularly in the UK, sometimes opt for a risk-based screening approach. This divergence highlights that medical best practices can evolve, and the conversation around these choices is ongoing within the medical community. Ultimately, the goal is always to support the healthiest possible start for your baby.
