A new study published in eNeuro, a journal for the Society of Neuroscience, shows that prematurity is linked to language and speech delays in babies. Premature birth is often linked to an increased risk of physical and cognitive delays or development problems, but the new study offers a focused look at how prematurity can cause brain damage.
According to the findings in eNeuro, children born in the early weeks of the third trimester are more likely to experience delays in development of crucial brain structures including the auditory cortex. The auditory cortex is the part of the brain essential to hearing. Delayed development of the auditory cortex can impact communication skills as the child grows up.
Prematurity and Delayed Brain Development
Prematurity is defined as a birth occurring before 37 weeks gestation. By this time, most of the critical systems of the body and brain are functional. However, as the eNeuro study notes, the earlier in the third trimester the birth is (the third trimester begins at 28 weeks gestation), the more likely that the child will suffer developmental issues.
Prematurity is traumatic for infants and makes them more vulnerable to many conditions and complications. One of the most common birth injuries related to prematurity is hypoxic ischemia, which occurs when the infant’s brain does not get enough oxygen, most often because of a lack of lung development. Hypoxic ischemia can occur before, during, or after birth. It can result from prematurity or a variety of other complications or conditions.
Focused Research on Prematurity and Brain Development
As early as the first trimester, or more specifically 15 weeks gestation, the basic neural systems related to hearing are functional, making babies at this early gestation already sensitive to language and speech related functions. A baby’s ears and basic auditory systems are functionally developed by 25 weeks gestation, but are not completely developed until five or six months after birth.
Researchers point to previous studies indicating that babies develop hearing, listening, and response mechanisms in the womb by 25 weeks gestation. Some studies have used ultrasounds to demonstrate babies blinking in response to external stimuli, such as sounds, voices, or music. Based on these previous studies, researchers have focused their efforts on the specific ways that prematurity can affect speech, hearing, and learning.
The article published in eNeuro discusses a recent study conducted analyzing brain scans of both premature and full-term infants. Researchers selected 90 premature infants who spent time in the neonatal intensive care unit at St. Louis Children’s Hospital between 2007 and 2010. For comparison, they selected 15 full-term infants at Barnes-Jewish Hospital in St. Louis. These 15 infants had undergone brain scans within four days of birth to show uninterrupted brain development.
As they analyzed the information, researchers focused on the primary auditory cortex, which is the first cortical region of the brain that receives auditory signals from the ears. They also looked closely at the nonprimary auditory cortex, which is part of the brain that does more advanced processing of information and facilitates speech and language. As they compared and analyzed, they considered the following questions:
- What is the relationship between these two parts of the brain?
- Do these two parts of the brain mature at the same time, but at different rates?
- Do these two parts of the brain mature at different times, but at similar rates?
The rates of maturation may affect how vulnerable each part of the brain is at different stages of development. To complete their study, researchers used diffusion neuroimaging, which studied the auditory cortex of each infant. Diffusion refers to the level of water in brain tissue, which changes as the brain grows and develops. Measuring diffusion allowed researchers to see changes in white and gray matter, and track development.
Conclusions Based on Study
Based on the research and analysis, researchers determined the following:
- By 26 weeks gestation, primary auditory cortex development was much more advanced than that of the nonprimary auditory cortex.
- Both auditory regions were less developed at 40 weeks among premature infants than in full-term infants.
- Between 26 and 40 weeks gestation (the period in which most premature births occur), the nonprimary auditory complex was still undergoing major changes in development.
In their quest for answers, researchers found a link between delayed development of the nonprimary auditory cortex and common language delays seen by age two. This finding suggests that damage or disruption to this part of the brain as a result of prematurity may contribute to language and speech problems often reported in children who were premature at birth.
For the future, doctors can use this and similar research as a guide to understanding how prematurity affects the brain. It can help doctors better predict potential language or speech issues in children born premature, which can result in better early intervention strategies.
What Parents Need to Know
Prematurity can be a scary prospect for expectant parents. Most early conversations about the possibility of premature birth include a lengthy list of possible complications or resulting conditions. As mentioned before, premature birth can be traumatic for the infant. Prematurity has been linked to:
- Behavioral and personality issues
- Attention deficit hyperactivity disorder
- Neurological disorders including autism
- Asthma and pulmonary problems
- Vision, hearing, and dental problems
- Increased risk of infection
Many of these conditions result from a lack of oxygen to the brain and vital organs. It is important that any signs of premature labor be taken seriously. Contact your healthcare provider if you have any symptoms of premature labor, or notice changes in the way your body and your baby feels or responds. The only way to determine if you are in labor is getting a thorough exam by a healthcare provider.
If you have legal questions or concerns about prematurity, related complications, or other birth injuries, contact Brown & Brothers. Our birth injury attorneys can help you understand your legal rights and determine your best options after a birth injury occurs. Fill out our online form to schedule a free case evaluation.