Investigating relations between the NICU speech environment and weight gain in infants born very preterm

BackgroundChildren born very preterm (< 32 weeks gestational age), are at risk for poor growth and adverse neurodevelopmental outcomes. Poor outcomes in preterm children have been attributed to the aversive sounds and relative speech paucity of the neonatal intensive care unit (NICU). Experimental studies that directly expose preterm infants to speech sounds in the NICU find significant improvements in health factors relevant for neurodevelopment. Few studies have examined whether natural variations in the speech environment of the NICU are related to short-term health outcomes in preterm infants. Such data are important for optimizing the sound environment of the NICU. ObjectiveExamine relations between the NICU speech environment and rate of weight gain during hospitalization, an important determinant of physical health and neurodevelopmental outcomes for preterm infants. MethodsParticipants were infants born very preterm (n = 20). The speech environment of each infant was assessed at 32-36 weeks postmenstrual age using a speech-counting device known as a Starling. Speech rates were averaged for each infant over the 4-week period. Average rates of weight gain (g/kg/day) were ascertained over the same period. Calories were derived from charted intake (kcals/kg/day). Linear regressions examined associations between weight gain and both caloric intake and speech counts. Control analyses explored whether effects remained after controlling for family visitation, time in incubator, and health acuity. ResultsInfants who received more calories gained more weight, accounting for more than 30% of the variance. Importantly, speech counts accounted for nearly 29% additional variance (p < .001). These effects were not reduced when controlling for family visitation, time in incubator, or health acuity. ConclusionsEnhancing speech exposure in the NICU may be beneficial for physical growth. NICU infant care plans should consider opportunities to increase speech exposure.