A randomized controlled trial to evaluate the efficacy and safety of a double-walled incubator compared to a radiant warmer in the care of extremely low-birth-weight infants

This study compared the safety and efficacy of double-walled incubators versus radiant warmers in extremely low-birth weight (ELBW: birth weight < 1000 g) preterm infants, hypothesizing that incubator care would reduce the time to regain birth weight compared with radiant warmer care. In this single-center, nonblinded, randomized controlled trial, ELBW infants with gestational age ≥25 to ≤32 weeks were randomized shortly after birth to stay in either an incubator or a radiant warmer for the first week of life, followed by radiant warmer care for all infants. The primary outcome was time to regain birth weight. Secondary outcomes included fluid intake, sodium levels, hypernatremia, and other neonatal outcomes. One hundred ELBW infants were enrolled. The median time to regain birth weight did not significantly differ between the incubator and radiant warmer groups: 12.00 (IQR 7.00, 17.75) days versus 11.50 (IQR 7.25, 15.75) days, respectively, with an effect size of median difference 0.0 (95% CI −4.0 to 4.0, P = .89). There were no significant differences in any other secondary outcomes. The study lacked sufficient power to detect differences in these outcomes. Either a double-walled incubator or a radiant warmer can be considered similarly safe and effective for thermoregulation and for achieving time to regain birth weight in ELBW infants. Radiant warmers may be preferable in low- and middle-income countries because they are less costly than double-walled incubators.