Comparative analysis of short term outcomes in Extremely Low Birth Weight infants <800grams (micro-preemies) in a tertiary care NICU between two time periods : a retrospective cohort study

ELBW neonates especially micro preemies (with birth weight <800 gm) constitute a very vulnerable subgroup of neonates, who are predisposed to higher rates of mortality and morbidities. If anticipated and managed timely, long-term survival of these neonates can be achieved. Although there has been improvement in survival of ELBW infants in developed nations, the survival of ELBW neonates in developing countries remains suboptimal due to lack of required infrastructure and good quality perinatal services. There is paucity of literature regarding mortality and morbidity data in LMICs. Data from a recent Cochrane review in 2021 suggests that for ELBW neonates, the survival in LI, LMI, and UMI countries was 18% (11% - 28%), 28% (21% - 35%) and 39% (36% - 42%), respectively. The overall survival in ELBW was 34% (95% CI: 31%

• 37%). In recent years, with good survival of VLBW neonates even in developing countries, the focus has been shifted to ELBW neonates for improving the survival of these vulnerable neonates. Data regarding improved survival among the micro-preemies post-enhanced perinatal care from this part of the country is still lacking. So, we have taken up this study to look at the mortality and morbidity outcomes of ELBW neonates (especially micro preemies with birth weight <800 gm) in 2 time periods in a tertiary level 3 NICU in South India (pre-covid and post covid periods). The reason for dividing into 2 separate time periods and comparing outcomes is COVID-19 pandemic in 2020. With improvements in perinatal and neonatal quality of services like Infrastructural changes including acquiring new equipment, strict implementation of hygiene measures, improved staff-to-patient ratio, and strict adherence to protocols survival of these micro-preemies might have improved over the years. This data would help to address the factors associated with the adverse outcomes, and good practices in NICUs associated with the improved survival of ELBW babies and also help to counsel the parents regarding the survival of micro preemies in the future.