What is Known: • GBS screening and intrapartum antibiotic prophylaxis led to a 32%-reduction in GBS disease in Germany with a 0.75 (92:122) ratio of early-onset disease to late-onset disease in 2009–2010. • Prenatal antibiotic use might increase the risk of E. coli early-onset disease and antibiotic resistances.

What is New: • The GBS early-onset disease rates were twice as high as those of late-onset disease, the ratio was 1.75 (21:12) in 2008–2018 at our institution. This suggests that there are at least regional implementation gaps in the antenatal GBS screening in Germany. • We found a decline in E. coli resistance rates over time for all antimicrobial substances. Reduction in use of prenatal antibiotics might be an explanation.