Weight gain in the first week of life and its association with morbidity and mortality in extremely low birthweight (ELBW) infants

Abstract

BackgroundWeight gain in the first week of life is indicative of fluid excess in preterm neonates. AimsTo determine if morbidity and/or mortality of extremely low birthweight (ELBW) infants was lower in those who did not have excess weight gain in the first week of life, compared with those who did. Study designRetrospective cohort study. SubjectsELBW infants born from 1st May 2014 – 31st May 2019. Exclusions: major congenital abnormalities (including hydrops), died within the first 7 days, no recorded weight on day 6, 7 or 8. Outcome measuresWe compared infants whose weight was greater than birthweight by day 7 and infants whose weight remained at, or below, birthweight by day 7. ResultsThere were 312 ELBW infants in the study population: 15 (5%) died before discharge from hospital. Holding birthweight and gestational age (GA) constant, the odds of death in neonates with day 7 weight >birthweight was about 3 times the odds of death in neonates with day 7 weight ≤birthweight (adjusted odds ratio 3.18, 95% confidence interval 0.66–15.26, p = 0.15). Neonates with day 7 weight >birthweight were more likely to have had a PDA that required treatment than those with day 7 weight ≤birthweight (65% versus 43% respectively; p <0.001). ConclusionsELBW infants who gain weight in the first week of postnatal life, have a greater risk of PDA requiring treatment and may have a higher risk of mortality than infants who lose weight in the first week of life.