How Mom's Voice Can Benefit a Preemie's Brain

A new study finds a premature baby's brain can get a boost from hearing its mother's voice and heartbeat.

Mother and newborn baby

It's no secret that babies born prematurely, before 37 weeks of pregnancy, may be at greater risk for health problems including long-term developmental disabilities. Many have trouble listening to and processing language sounds. However, a study recently published in the Proceedings of the National Academy of Science offers some hope: The simple act of hearing their mother's voices and heartbeats may make a difference for these infants.

For the study, researchers examined 40 infants born between 25 and 32 weeks at Brigham and Women's Hospital in Boston. They spent most of their time in incubators (which is the norm for babies born prematurely). Through tiny speakers inside the incubators, about half the infants were randomly assigned to hear recordings of their mother's heartbeats as well as their moms singing "Twinkle, Twinkle, Little Star" and reading Goodnight Moon out loud for three hours a day. The other babies only heard the standard noises in the hospital.

Researchers found that after 30 days, those infants who heard the maternal sounds had a significantly larger auditory cortex—the part of the brain that controls hearing and processing of sounds—compared with that of the other babies. That system in the brain seemed to adapt better to sounds that babies would normally hear in the womb rather than environmental noises in the hospital. "The results of this study suggest that in the case of babies born prematurely, exposure to maternal sounds may set the auditory cortex of the brain on the right trajectory for completing its maturation outside the womb," explains study co-author Amir Lahav, ScD., assistant professor of pediatrics at Harvard Medical School.

Experts say that these findings suggest that NICUs might want to reconsider the parents' role during those critical days and weeks after babies are born prematurely. "It is important that mothers understand that live talking, singing, and interacting with their babies during NICU visits cannot be simply replaced by recorded maternal sounds; however, the use of recorded sounds inside the incubator gives mothers the opportunity to virtually be with their babies when they are unable to physically be there," says Dr. Lahav.

Of course, whether or not your baby was born prematurely, it's always important to spending plenty of time talking to her. In fact, research has shown that a baby's intelligence and language abilities are correlated to how much her parents speak to her between birth and age 3. In other words, it's never too soon to engage in baby talk, so start chatting (or singing!) away.