Brain Volumes in Mice are Smaller at Birth After Term or Preterm Cesarean Section Delivery.

The rate of cesarean section (CS) delivery has steadily increased over the past decades despite epidemiological studies reporting higher risks of neonatal morbidity and neurodevelopmental disorders. Yet, little is known about the immediate impact of CS birth on the brain, hence the need of experimental studies to evaluate brain parameters following this mode of delivery. Using the solvent clearing method iDISCO and 3D imaging technique, we report that on the day of birth, whole-brain, hippocampus, and striatum volumes are reduced in CS-delivered as compared to vaginally-born mice, with a stronger effect observed in preterm CS pups. These results stress the impact of CS delivery, at term or preterm, during parturition and at birth. In contrast, cellular activity and apoptosis are reduced in mice born by CS preterm but not term, suggesting that these early-life processes are only impacted by the combination of preterm birth and CS delivery.