PathAdvantage | 12/03/2025Group B Streptococcus (GBS) is one of the most important — yet often overlooked — infections screened for during pregnancy, because identifying it early can make all the difference in protecting a newborn’s health.
Why is GBS Testing Important?
Group B Streptococcus is a type of bacteria naturally carried by about 1 in 4 pregnant women. Most of the time it causes no symptoms, but if passed to a baby during delivery, it can lead to serious infections, such as pneumonia, sepsis or meningitis. Fortunately, if GBS is detected before birth, it can be easily treated with antibiotics, preventing almost all cases of newborn infection.
For decades, GBS screening relied on a culture test. This method involves collecting a swab from the mother and waiting for bacteria to grow in the lab which often takes 2 to 3 days. While a culture can detect GBS, it is less sensitive (meaning that it can miss some cases) and can be too slow when results are needed quickly; especially for women who go into labor before results are available. Since only about 57% of births are full term and pre-term deliveries are becoming more common, it is not unusual for doctors to still be waiting on a GBS result even as labor begins.
What is PCR?
PCR, or Nucleic Acid Amplification Testing (NAAT), detects the genetic material (DNA) of GBS directly, without waiting for it to grow in a culture. This technology is
- Faster – results are available within hours rather than days.
- More accurate and sensitive – PCR can find even very small amounts of bacteria that culture might miss.
- More reliable – less affected by transport conditions or human error during sample handling.
Why PathAdvantage Switched to PCR for GBS Testing
We evaluated multiple testing options and chose the Hologic Panther Fusion GBS Assay for its combination of speed, accuracy, and ease of use. Our studies showed:
- 100% precision and perfect agreement with other validated methods. (The Panther Fusion actually performed better than our previous method. See next point!)
- Greater sensitivity – detecting some GBS-positive samples that older tests had missed.
- Turnaround times under 24 hours for 96% of samples, supporting same-day clinical decisions.
What This Means for our Doctors and Their Patients
PCR-based GBS testing means:
- Faster peace of mind: results often within a day.
- Higher confidence in your results, and fewer missed infections.
- Better protection for you and your baby, allowing timely antibiotics if needed.
- In short, PCR gives both patients and doctors the most accurate, rapid, and dependable way to detect GBS, helping ensure a safer, healthier delivery.
By using advanced PCR testing for GBS, PathAdvantage gives doctors and patients faster, more accurate answers — and the peace of mind that comes with knowing every baby has the safest possible start.