ASSOCIATION OF MATERNAL AND NEONATAL RISK FACTORS WITH EARLY ONSET NEONATAL SEPSIS

Abstract

BACKGROUND Early-onset neonatal sepsis (EONS) remains a significant cause of neonatal morbidity and mortality, particularly in low- and middle-income countries. It is primarily acquired through vertical transmission and is influenced by a combination of maternal, intrapartum, and neonatal factors. Identifying locally relevant risk factors is essential for improving early recognition, guiding preventive strategies, and optimizing neonatal care. OBJECTIVE To determine the association between selected maternal and neonatal risk factors and the occurrence of early-onset neonatal sepsis among neonates admitted to the neonatal unit of Combined Military Hospital (CMH) Abbottabad. METHODS A hospital-based unmatched case–control study was conducted over five months, from 15 August 2024 to 15 January 2025, at CMH Abbottabad. Neonates aged ≤72 hours admitted to the NICU were enrolled. A total of 240 neonates were included in the final analysis after exclusions, comprising 120 cases diagnosed with EONS and 120 controls admitted for non-infectious conditions. Data on maternal, intrapartum, and neonatal variables were collected using a structured proforma. EONS was defined based on clinical features and supportive laboratory findings, with or without a positive blood culture. Statistical analysis was performed using appropriate univariate tests, followed by multivariate logistic regression to identify independent predictors of EONS. Adjusted odds ratios (AORs) with 95% confidence intervals were reported. RESULTS Among the 120 EONS cases, 38 (31.7%) were culture-positive. Maternal factors significantly associated with EONS included unbooked antenatal status (40.8% vs 20.0%, p=0.001), maternal anemia (43.3% vs 24.2%, p=0.002), urinary tract infection (32.5% vs 15.0%, p=0.002), genital tract infection (15.8% vs 6.7%, p=0.03), prolonged rupture of membranes ≥18 hours (34.2% vs 10.0%, p<0.001), intrapartum fever ≥38°C (21.7% vs 5.8%, p<0.001), and suspected chorioamnionitis (15.0% vs 3.3%, p=0.002). Neonatal factors significantly associated with EONS included preterm birth (25.8% vs 13.3%, p=0.01), low birth weight (54.2% vs 30.0%, p<0.001), Apgar score <7 at 1 minute (24.2% vs 10.8%, p=0.008), and need for resuscitation at birth (19.2% vs 7.5%, p=0.009). On multivariate analysis, independent predictors of EONS were prolonged rupture of membranes (AOR 3.82), maternal intrapartum fever (AOR 4.11), preterm birth (AOR 2.34), low birth weight (AOR 2.97), maternal urinary tract infection (AOR 1.96), and unbooked antenatal status (AOR 2.12). Group B Streptococcus (28.9%) and Escherichia coli (26.3%) were the most commonly isolated organisms. CONCLUSION Early-onset neonatal sepsis in this setting is strongly associated with preventable maternal risk factors and neonatal vulnerabilities. Prolonged rupture of membranes, maternal intrapartum fever, untreated maternal urinary tract infection, inadequate antenatal care, prematurity, and low birth weight were the most significant predictors. Strengthening antenatal screening, improving intrapartum monitoring, and ensuring early neonatal surveillance for at-risk infants may substantially reduce the burden of EONS in similar resource-limited settings.