Associations of preterm birth and postnatal growth with brain maturation

The comorbidity of preterm birth and suboptimal postnatal growthin infants may be negatively associated with brain maturation, according to a recent study published in JAMA Network Open.

The risk of adverse neurodevelopmental outcomes is greater in children born very preterm, with postnatal growth failure (PGF) and associated outcomes playing a vital role in morbidity. Growth failure during a critical period can lead to poor neurodevelopmental outcomes in preterm infants.

Using magnetic resonance imaging (MRI) and diffusion tension imaging, investigators have determined cerebral structural development changes associated with preterm birth. Associations have also been determined between brain structure development and postnatal growth.

As the effects of postnatal growth on brain structure development in infants born preterm are unclear, investigators conducted a prospective cohort study to determine the association between these factors.

Participants included children born with extremely low birth weight (ELBW) and were grouped based on postnatal growth pattern. Having a weight under the third percentile for postmenstrual age was criteria for PGF. 

Children were excluded if they had a severe brain injury or birth weight below the third percentile. A control group was composed of children born at full term with typical development and were age-matched to the ELBW group.

MRI testing was conducted in participants aged 6 to 8 years alongside neuropsychological tests conducted by psychologists unaware of the patients’ postdischargedetails and perinatal findings. Cognitive skills, executive function (EF), and attention function were tested in patients.

The same scanner and protocol were used for all participants during MRI scanning. Eighteen major white matter tracts were analyzed.

A total of 82 MRI scans were evaluated from 21 children with PGF born preterm, 17 children without PGF born preterm, and 44 children born full term. A higher gestational age (GA) and lower birth weight was found in children with PGF compared to those without PGF.

Children born with PGF had a mean GA of 27 weeks and 5 days and a mean birth weight of 801.1 g. Children born without PGF had a mean GA of 26 weeks and 1 day and a mean birth weight of 830.7 g. No significant differences in morbidities were found between children with and without PGF.

Individuals in the control group had a higher Full-Scale Intelligence Quotient (FSIQ) score than the preterm groups with and without PGF. FSIQ scores were significantly lower in children with PGF compared to those without PGF.

Average EF scores were also significantly higher in children born at full term, while children without PGF had higher EF scores than those with PGF. Children with PGF also had a significantly higher Advanced Test of Attention score on average, which is associated with poorer function.

Brain developmental outcomes were also shown to be worse in children with PGF born preterm, in multiple areas of the brain. These results indicate negative associationsfor brain developmental with preterm birth and suboptimal postnatal growth.

Reference

Kim SY, Kim E, Song H, et al. Association of brain microstructure and functional connectivity with cognitive outcomes and postnatal growth among early school–aged children born with extremely low birth weight. JAMA Netw Open. 2023;6(3):e230198. doi:10.1001/jamanetworkopen.2023.0198