Impact of antibiotic duration and type on short- and long-term outcomes in very-low-birthweight infants.

Aim: To determine the association between the duration and types of antibiotic exposure and the occurrence of short- and long-term outcomes among preterm, very-low-birthweight (VLBW) infants.

Methods: Retrospective cohort study of VLBW infants born <32 weeks gestation between January 2017-December 2021. Association between antibiotic exposure and the occurrence of death and/or major morbidities, and neurodevelopmental impairment (NDI) at 18-24 months corrected age, was evaluated.

Results: A total of 728 infants were included-median gestation 28 weeks (IQR 26, 30) and median birthweight 1070g (IQR 850, 1300). Compared to no antibiotics, antibiotics exposure >3 days was significantly associated with increased risk of mortality and/or bronchopulmonary dysplasia (BPD)-adjusted odds ratio (AOR) 2.0 (95% CI 1.1-3.8; p=0.03), 3.5 (95% CI 1.6-7.8; p=0.01) and 3.8 (95% CI 1.6-9.0; p<0.001) corresponding to antibiotic exposure of 4-7 days, 8-14 and >14 days, respectively. Additional exposure to broad-spectrum antibiotics was associated with AOR of 3.2 (95% CI 1.6-6.5; p<0.01) for death and/or BPD. There was no significant association between antibiotic exposure and NDI.

Conclusion: Infants who received >3 days of antibiotics and/or additional broad-spectrum antibiotics had significantly increased odds of death and/or BPD compared to no exposure. Antibiotic exposure was not significantly associated with NDI in our population.