Trends in Perinatal Group B Streptococcal Disease After Updated Screening Recommendations in the United States

Area of Science:

• Obstetrics and Gynecology
• Neonatal Health
• Infectious Disease Epidemiology

Background:

• The American College of Obstetricians and Gynecologists updated prenatal group B streptococcus (GBS) screening recommendations in 2019.
• The update shifted the recommended screening window to 36 0/7–37 6/7 weeks of gestation.
• This change aimed to ensure accurate test results for pregnant individuals up to 41 0/7 weeks gestation.

Purpose of the Study:

• To evaluate the impact of the updated GBS screening guideline on neonatal GBS early-onset disease (EOD) and mortality rates.
• To compare disease and death rates in the periods before and after the guideline change.
• To assess the effectiveness of the revised screening timing.

Main Methods:

• Retrospective analysis of neonatal GBS EOD and death cases.
• Data collected from the Centers for Disease Control and Prevention's Active Bacterial Core surveillance system.
• Comparison of rates during the prechange period (2016-2018) and postchange period (2020-2022).

Main Results:

• A total of 2,640 cases were reported in the prechange period (0.24±0.01 cases/1,000 live births).
• In the postchange period, 2,120 cases were reported (0.20±0.02 cases/1,000 live births).
• The annual percent change (APC) for GBS EOD declined from 2.1% in the prechange period to -9.6% in the postchange period.

Conclusions:

• Neonatal GBS EOD rates significantly declined in the three years following the updated screening guideline implementation.
• The findings support the current practice of shifting prenatal GBS screening timing.
• The updated guidelines appear effective in reducing the burden of early-onset GBS disease in newborns.