Maternal–Fetal Infectious Risk and Early Antibiotic Treatment Patterns in Late Preterm and Term Newborns in a Romanian Secondary-Care Maternity: A Six-Month Observational Cohort

<b>Background:</b> Microbiological confirmation of early-onset neonatal infection is inconsistently available in many secondary-care maternity units, and early management often relies on maternal risk profiles and inflammatory markers. <b>Objectives:</b> This study aimed to describe maternal infectious risk factors, neonatal biomarkers, and early antibiotic treatment patterns among late preterm and term newborns evaluated for suspected maternal-fetal infection (MFI) in a Romanian secondary-care maternity, and to explore whether a simplified bedside indicator (NeoSIR) corresponded with antibiotic initiation and treatment-related outcomes. <b>Methods:</b> Observational cohort study (April-September 2024) including newborns with gestational age ≥ 35 weeks evaluated within 24 h for suspected MFI based on maternal risk factors and/or neonatal clinical findings. We recorded maternal infections and screening results, neonatal complete blood count and C-reactive protein (CRP) at 24 h, cultures obtained as part of routine care, antibiotic initiation, treatment duration, and neonatal intensive care unit (NICU) admission. <b>Results:</b> Among 443 newborns, empirical antibiotics were initiated in 414 (93.5%) and 62 (14.0%) required NICU admission. Maternal urinary tract infection (UTI) documented during pregnancy (recorded diagnosis and/or positive urine culture and/or treatment) was associated with antibiotic initiation (<i>p</i> = 0.005). Elevated CRP (>0.5 mg/dL) was associated with antibiotic selection (<i>p</i> = 0.032) and longer therapy (mean 8.33 vs. 6.98 days, <i>p</i> < 0.001); courses were also longer in NICU-admitted infants (mean 10.39 vs. 6.81 days, <i>p</i> < 0.001). The exploratory two-item NeoSIR indicator (maternal UTI and CRP > 0.5 mg/dL) was feasible to compute but showed limited discrimination for antibiotic initiation in this high-treatment cohort. <b>Conclusions:</b> In this selected high-risk cohort, antibiotic exposure was highly prevalent and closely associated with maternal urinary tract infection history and neonatal CRP evolution. These findings primarily describe early management patterns in a secondary-care maternity with limited microbiological confirmation and should be interpreted as hypothesis-generating. The exploratory NeoSIR indicator is not intended as a diagnostic or decision-support tool and requires validation against culture-confirmed outcomes in more heterogeneous populations.