Babies born early in the third trimester may show signs of delayed auditory cortex development, which is a part of the brain that helps infants hear and understand sounds. This can influence the development of a baby's communication skills as they get older. The findings might even help doctors successfully screen babies who could undergo difficulties so they can receive the help they need beforehand.
An infant is considered premature once it is born before 37 weeks of gestation. If a smaller baby is born earlier, it has a higher risk of health and developmental problems such as speech, hearing, and language. (Related: Vitamin D Cuts Premature Birth Risk.)
Fifteen weeks before an infant is born, the neural machinery that supports their hearing is often already functional and they are already sensitive to human speech and language. By the 25th week of gestation, an unborn baby's ears have already formed. Their brain's auditory system is also developed enough to be functional, which continues to grow until the infant is five to six months old.
Dr. Brian Monson, from the University of Illinois and a study author, shares that we have yet to fully understand the auditory brain development of preterm infants. Based on earlier studies, full-term newborns can already hear, listen, and learn.
However, speech and learning delays are more common among pre-term infants than those born after 39 weeks in the womb, and Dr. Monson et al. decided to look into the "differences in the developments of pre- and full-term babies' brains" and when they occurred to figure out what can go wrong with premature infants.
For the study, researchers examined the brain scans of 90 preemies in the neonatal intensive care unit at the St. Louis Children's Hospital from 2007 to 2010. The first group of infants was then compared to the second group of 15 full-term babies at Barnes-Jewish Hospital with scans taken during the first four days of their birth to "show uninterrupted fetal brain development."
The scientists looked into the primary auditory cortex, which is the first cortical region to receive auditory signals from the ears through other parts of the brain. They also observed the non-primary auditory cortex, which has a more complex role when processing the information which aids the development of language and speech.
The findings of the study determined that within the 26th week of gestation, the primary auditory cortex is in a more advanced stage of development compared to the non-primary auditory cortex in all babies. The two regions were less developed at 40 weeks in preemies compared to the full-term babies.
Dr. Monson explains that infants born prematurely are more susceptible to injuries such as hypoxic ischemia, or when the brain doesn't get oxygen since the lungs "aren’t mature enough." Injuries like this can damage the fragile non-primary auditory cortex, which can cause common speech and language comprehension problems scene in preemies.
The study isolated a link between the delayed development of the non-primary auditory cortex in infancy and language delays in children aged two years old. This link implies that disruptions in this region of the brain are caused by premature birth and that it is partly responsible for the speech and language problems experienced by some preemies.
Dr. Monson notes that more research is required to confirm if the link "between auditory cortex maturity in infancy and language outcomes" is present as the babies grow older. He concludes that helping infants along by repeating certain language and speech sounds can somehow prevent the speech and language delays among preemies. Mothers can try reading to babies and showing them pictures in books.
Mothers should also encourage preemies to imitate the words they say. Don't use "baby talk," and talk to the infants frequently using short and simple sentences.
You can read more articles about infant health and pregnancy news at WomensHealth.news.