Severe cell reduction in the future brain cortex in human growth–restricted fetuses and infants

Objective The objective of the study was to test the hypothesis that the total number of cells in the cortical part of the cerebral wall is the same in intrauterine growth–restricted (IUGR) fetuses, compared with normally grown fetuses. Study Design The total cell number in the cerebral wall was estimated in 9 severely affected IUGR fetuses and 15 controls using the optical fractionator. Cell numbers were estimated within 4 developmental zones. The gestational ages were 19-41 weeks. Results The total cell number in the future cortex was significantly reduced in the IUGR fetuses, compared with controls. The daily increase in brain cells in the future cortex was only half of that of the controls. In the 3 other developmental zones, no significant differences in cell numbers could be demonstrated. Conclusions IUGR in humans is associated with a severe reduction in cortical growth and a significant decrease in cell number in the future cortex.