Group B streptococcus (GBS) screen

Microbiology

Notes

• The information given here is intended for use by healthcare professionals. Please see Lab Tests Online-UK for more general advice, links and background.
• This investigation is performed on selected patients in late pregnancy to assess for carriage of group B streptococci (Streptococcus agalactiae).
• Selective testing follows national guidelines. Testing is done to reduce the incidence of early onset group B streptococcal (GBS) infection in neonates.
• Current methodology is based on culture.
• See also:
  • Female genital tract swabs (HVS, endocervical, vulval)

Sample requirements

Standard charcoal transport swab

Lower vaginal swab

Place swab into transport medium

Required information

• Gestation
• Any risk factors for GBS infection

Storage/transport

Store and transport at room temperature. Samples should be transported to the laboratory with minimal delay.

Turnaround time

Negative 1 - 2 days

Positive 2 - 3 days