European researchers have used 3D ultrasound to measure cortical folding, which increases the surface area of the brain and therefore its processing power, in fetuses with congenital heart defects. Their primary interest was in finding out whether prenatal cardiovascular anomalies affect neurodevelopment, although they also wanted to see if measuring the depths of the crevices reliably indicates the extent of folding.

Irene Koning, MD, of Erasmus University in the Netherlands and colleagues scanned the brains of 20 fetuses with congenital heart defects and 193 healthy controls at 22, 26 and 32 weeks gestational age.

The researchers measured brain fissure depths in several regions and obtained Doppler indices of the umbilical artery and middle cerebral artery, calculating the cerebroplacental ratio.

Analyzing associations between heart defects and cortical folding, they found decreased growth trajectories in the heart-defect fetuses compared to the controls.

They also found that brain fissure measurements were successfully acquired in more than 80 percent of the scans, and all measurements had good reliability scores.

Additionally, in contrast to the controls, they found no associations between cerebroplacental ratio and cortical folding in the congenital heart defect cohort.

“Fetal cortical folding can be evaluated reliably by measuring brain fissure depths,” the authors conclude. “Trajectories of cortical folding between 22 and 32 weeks gestational age seem to be influenced by congenital heart defects.”