What screening is recommended for Group B Streptococcus during pregnancy?

The recommended screening for Group B Streptococcus (GBS) during pregnancy is a vaginal-rectal culture performed at 35-37 weeks of gestation. This timing is crucial because it allows for the identification of GBS colonization in the mother right before delivery, when the potential risk of transmission to the newborn is highest.

Screening at this stage helps in determining the need for intrapartum antibiotic prophylaxis during labor to reduce the risk of early-onset GBS disease in the newborn. If a mother tests positive for GBS, antibiotics can be administered during labor to significantly lower the chances of the baby developing an infection. This practice has been well-studied and is a standard part of prenatal care in many health systems to safeguard neonatal health.

Other testing methods, such as blood tests or urine tests at different points during pregnancy, are not effective for GBS screening. Blood tests are not reliable for detecting GBS colonization, and while urine tests can detect infection, GBS is normally present in the gastrointestinal and genital tracts rather than the urine and does not reflect the risk of transmission during delivery. Lastly, waiting for symptoms to appear does not align with the guidelines since GBS colonization is often asymptomatic, making