What is being analysed?

Prenatal screening for Group B strep (GBS) involves testing for the presence of the bacteria strep agalactiae in the genital and rectal areas of pregnant individuals.

What does the result mean?

A positive result indicates that the individual is colonised with GBS, meaning the bacteria is present in their body. A negative result means that GBS was not detected during the screening.

Why do the analysis?

The analysis is performed to identify pregnant individuals who are carriers of GBS. Carriers can transmit the bacteria to their newborns during childbirth, potentially causing serious infections such as pneumonia, sepsis, or meningitis.

When to do the analysis?

Prenatal screening for GBS is typically conducted between the 35th and 37th week of pregnancy. This timing allows for appropriate management strategies to be implemented if GBS colonisation is detected.

What sample is required?

The sample required for GBS screening is obtained through a swab of the vaginal and rectal areas.

Is any type of prior preparation necessary?

No specific prior preparation is necessary for GBS screening.

How is it used?

The results of GBS screening inform healthcare providers about the need for intrapartum antibiotic prophylaxis (IAP) during labour and delivery. If a pregnant individual tests positive for GBS colonisation, they will receive antibiotics during labour to reduce the risk of transmitting the bacteria to the newborn.

What are the normal values?

The normal value for GBS screening is a negative result, indicating the absence of GBS colonisation.

What does it mean to have altered values?

A positive result indicates GBS colonisation, which requires the administration of antibiotics during labour to prevent transmission to the newborn. Failure to receive appropriate IAP in cases of GBS colonisation increases the risk of neonatal GBS infection.

Table of Values: