A modified newborn intensive care unit environment may shorten hospital stay

Premature infants with birth weights from 1121 to 2000 gm were assigned randomly to two groups. Experimental group infants were placed on a microprocessor-controlled cradle that provided levels of motion and sound analogous to those of the third-trimester intrauterine environment. Periods of motion totaling 50% of the time were randomized on and off; motion speed was reduced 35% during a 12-hour night period. A uterine souffle sound was generated continuously but varied in pulse rate and volume with the motion and speed of the bed. Experimental group infants (n = 20) were placed on the cradle under a radiant warmer as soon as their condition was stable clinically. Control group infants (n = 18) were usually placed initially under a radiant warmer and transferred to an incubator when their condition was stable. Otherwise, both groups received standard newborn intensive care unit care. The mean length of hospital stay was significantly shorter for experimental group infants than for control group infants after controlling for gestational age and weight on entry to the study. Experimental group infants began nippling earlier and stopped requiring gavage feedings sooner. Experimental group infants had a decreased incidence of apnea. Blinded Brazelton Neonatal Behavioral Assessment Scale scores for the Orientation and Range of State cluster scales were significantly better for experimental group infants. A retrospective contrast group of preterm infants who met study criteria had an average length of stay similar to that of the control group infants. These data support the hypothesis that appropriate levels and kinds of stimulation may facilitate the maturation of preterm infants.