Time to Regain Birthweight and Association with Neurodevelopmental Outcomes among Extremely Preterm Newborns.

Objective: Determine association between time to regain birthweight and 2-year neurodevelopment among extremely preterm (EP) newborns.

Study Design: Secondary analysis of the Preterm Erythropoietin Neuroprotection Trial evaluating time to regain birthweight, time from birth to weight nadir, time from nadir to regain birthweight, and cumulative weight loss with 2-year corrected Bayley Scales of Infant and Toddler Development 3rd edition.

Results: Among n = 654 EP neonates, those with shorter nadir-to-regain had lower cognitive scores (2-4 days versus ≥ 8 days: -3.5, [CI -7.0, 0.0]; ≤1 day versus ≥ 8 days: -5.0, [CI -10.2, 0.0]) in fully adjusted stepwise forward regression modeling. Increasingly cumulative weight loss was associated with lower cognitive scores (-50 to <-23 percent-days: -4.0, [95% CI -7.6, -0.4]) and language scores (≤-50 percent-days: -5.7, [CI -9.8, -1.6]; -50 to <-23 percent-days: -6.1, [CI -10.2, -2.0]).

Conclusion: Faster nadir-to-regain and prolonged, severe weight loss are associated with adverse 2-year neurodevelopmental outcomes.

Trial Registration: PENUT Trial Registration: NCT01378273. https://clinicaltrials.gov/ct2/show/NCT01378273.