According to the preliminary findings of a new study, newborns staying in the neonatal intensive care unit (NICU) tend to sleep better if they can listen to a recording of their mother’s voice. The sleep benefits appear to be stronger for babies who are closer to full term than for those born more prematurely.
Approximately 10 percent of newborns in the United States require treatment in a NICU, often a very noisy environment. For the study, the researchers investigated whether infants’ exposure to their mother’s voice in the NICU could soften the impact noise can have on newborn sleep pattern development.
The findings suggest that newborns staying in the NICU were less likely to be awakened by noises when a recording of their mother’s voice was playing. The researchers also found that newborns born at or after 35 weeks gestation show sleep-wake patterns that appear to respond increasingly with age to recorded maternal voice exposure. However, this association did not seem to apply to infants born before 35 weeks gestation.
“Exposure to a mother’s voice recording may insulate NICU patients from some of the impact of unavoidable noise by reducing the likelihood of wakefulness during the highest peak noise levels,” explains Principal investigator Dr. RenĂ©e Shellhaas, a clinical associate professor of pediatrics in the division of Pediatric Neurology at the University of Michigan.
The study involved 20 newborn babies born at or after 35 weeks gestation and 27 infants born preterm at 33-34 weeks. Their mothers were recorded reading children’s books. The newborns underwent a 12-hour sleep evaluation by attended polysomnography. Each mother’s recording was randomized to be played continuously for her child during either the first or second 6-hours of the polysomnogram.
Newborn babies who are ill or born prematurely may require extended care in a neonatal ICU during a time of critical brain development. The findings suggest that interventions developed to help improve sleep in newborns who must stay in an intensive care unit may need to be tailored according to gestational age.
“Our study results suggest an intervention as simple as playing a recording of the mother reading stories may result in improved sleep,” said Shellhaas. “However, the impact of such interventions appears to be more significant for newborns who are near term gestation than for more premature infants.”