Antibiotic exposure and EARLY adverse outcomes in preterm, very low BİRRTH wei̇ght i̇nfants

Purpose: Antibiotics are among the most commonly used medicines in premature newborns admitted to NICUs. Misuse of the antibiotics may contribute to an increased risk for late onset sepsis (LOS), necrotizing enterocolitis (NEC), and mortality. In this study, we aimed to determine risk factors for LOS and NEC and identify whether early use and duration of antibiotics increase that risk. Material and Method: We performed a retrospective analysis of 229 very low birth weight infants (VLBW) admitted to NICU of Bezmialem University Medical Faculty Hospital between January 1, 2011 and December 31, 2021. The choice and duration of antibiotics, frequencies of LOS and NEC, and mortality were evaluated. Results: Prematurity (100%), maternal hypertension (37.6%), prolonged rupture of membranes (16.6%) and NEC (13.6%) were the most common risk factors associated with sepsis. 87.3% VLBW newborns received empiric antibiotic therapy. Ampicillin and gentamicin were the most commonly used antibiotics. The duration of therapy with empirical antibiotics in VLBW newborns was 6,5 +/- 3,4 days. Mean duration of therapy was 7 days with the range of duration being between 0 and 17 days. 68.1% of the cases received antibiotics for more than 5 days. The frequency of LOS and NEC were 43.7% and 13.6% respectively. Using univariate analysis, antibiotic use increased the risk of LOS (OR: 4,34, %95 CI). However, no significant link was detected in multivariable analysis. The duration of antibiotic therapy (Days of therapy, DOT) was longer in patients who developed NEC than those without NEC (95 days, 27 days, p<0,001). Mortality rate was 7% and was not associated with prolonged antibiotic use. In univariate analysis, postnatal steroid use was found to be associated with an increased risk of LOS and NEC (OR: 9,11/ OR:4,64). Conclusion: This study shows that although there is not a significant correlation between empirical antibiotics with NEC and mortality, LOS risk may increase with prolonged use of early antibiotics. These results emphasize the importance of avoiding unnecessary antibiotic use. Key words: neonatal sepsis, antibiotic use in newborns, necrotising enterocolitis