PurposeThis study was designed to determine whether supine positioning of infants born preterm in a hammock instead of the prone position affects their neuromuscular maturity, growth, and autonomic stability.MethodsTwenty healthy infants who were born premature with very low birth weight (VLBW) (<1500 g) were randomized into two groups. Subjects were pair-matched for weight (difference less than 100 g), gestational age (difference less than eight days), and postnatal age (difference less than eight days). Ten infants were placed supine in a hammock for three hours daily for ten consecutive days, and ten infants were maintained nested in the prone position. Neuromuscular maturity (based on three neurological parameters adopted from the Ballard examination), heart rate, respiratory rate, and weight gain (g/cal) were compared between the groups.ResultsCompared with nested prone positioning, supine positioning in a hammock was associated with a higher neuromuscular maturity score (p< 0.003) and a more relaxed condition, as expressed by lower heart rate and respiratory rate (p< 0.05 andp< 0.01, respectively).ConclusionsMaintaining infants who were born preterm with VLBW in the supine position in a hammock may positively affect their autonomic stability and neuromuscular maturity.