Group B Streptococcus is a bacterial infection that can be particularly prevalent during pregnancy. Although it often does not have symptoms in the pregnant person, they can pass it on to their newborns during birth. Group B strep infections in newborns can be more serious, potentially causing sepsis, pneumonia or meningitis. It’s therefore recommended that providers screen patients during pregnancy for Group B strep.
The American College of Obstetricians and Gynecologists updated the guidelines for screening during pregnancy in 2019, which were reaffirmed in 2025. The updated guidelines shifted when the screening should occur from 35-37 weeks gestation to 36-37 weeks gestation, hopefully providing greater accuracy for results up through 41 weeks.
In August 2025, a study reported on the change in Group B strep infection incidence following the guideline update. The study showed a decline in the rate of infections, from 24 cases per 1,000 live births in 2016-2018 to 20 cases per 1,000 live births in 2020-2022. The rate had been increasing by 2.1% per year before the guideline update, but after the update in guidelines, the rate declined by 9.6% per year.
Here is the full study: Trends in Perinatal Group B Streptococcal Disease After Updated Screening Recommendations in the United States.