Every Day That Fetuses Remain in Utero Critical to Preserving Normal Brain Development
Framingham-like cohort of healthy fetuses point to activities to support developing brains
During the third trimester – the final 13 to 14 weeks of gestation – fetuses’ brains grow exponentially, and the body shifts energy to the brain to accommodate the neurological growth spurt. As the brain size increases four-fold, it develops critical structures and connections that will be relied upon for life.
However, some 15 million infants around the world – and 1 in 10 American babies – are born prematurely. While researchers have known that preemies’ brain growth is disturbed when compared with infants born at full term, it remained unclear when preemies’ brain development begins to veer off course and how that impairment evolves over time, says Catherine Limperopoulos, PhD, Director of the Developing Brain Research Laboratory at Children’s National Health System and senior study author.
In order to shine a spotlight on this critical phase of fetal brain development, Limperopoulos and colleagues studied 75 preterm infants born prior to the 32th gestational week who weighed less than 1,500 grams who had no evidence of structural brain injury. These preemies were matched with 130 fetuses between 27 to 39 weeks gestational age.
The healthy fetal counterparts are part of a growing database that the Children’s National Developing Brain Research Laboratory has assembled. Just as school kids have annual physicals in which their height, weight, and other key metrics are recorded, the research lab uses three-dimensional magnetic resonance imaging to carefully record week-by-week development of the normal in utero fetal brains as well as week-by-week characterizations of specific regions of the fetal brain. Think Framingham, but for fetuses.
The availability of time-lapsed images of normally developing brains offers a chance to reframe research questions in order to identify approaches to prevent injuries to the fetal brain, Limperopoulos says.
“Up until now, we have been focused on examining what is it about being born too early? What is it about those first few hours of life that leaves preemies more vulnerable to brain injury?” she says. “What is really unique about these study results is for the very first time we have an opportunity to better understand the ways in which we care for preemies throughout their hospitalization that optimize brain development and place more emphasis those activities.”
When the research team compared third-trimester brain volumes, preemies showed lower volumes in the cerebrum, cerebellum, brainstem, and intracranial cavity. The cerebrum is the largest part of the brain and controls speech, thoughts, emotions, learning, as well as muscle function. The cerebellum plays a role in learning and social-behavioral functions as well as complex motor functions; it also controls the balance needed to stand up and to walk. The brainstem is like a router, ferrying information between the brain, the cerebellum, and the spinal cord.
“What this study shows us is that every day and every week of in utero development is critical. If at all possible, we need to keep fetuses in utero to protect them from the hazards that can occur in the extra uterine environment,” she says.
Contact: Diedtra Henderson | Children’s National Health System | c: 443-610-9826/o: 202-476-4500 | [email protected]