3.3. Brain lobes
Cerebral lobes show different growth rates during the first weeks of life in both sexes (Gilmore JH et al., 2018). The fastest growth rate is exhibited by the frontal lobe (4.44 ml/week), followed by the parietal lobes (2.93 ml/week), temporal lobes (2.29 ml/week), occipital lobes (2.40 ml/week), and lastly the limbic regions (0.58 ml/week) (Nishida M et al., 2006). The frontal and temporal lobes continue their growth during the first two years after birth with significant growth of the frontal lobe over the temporal lobes (Matsuzawa J et al., 2001). A significant sex difference was found in the total volume of frontal and temporal lobes in infants where 2-5 weeks-old males had greater volumes, while females of the same age had greater volumes of the left parietal and right temporal lobes (Lehtola SJ et al., 2019). Moreover, male infants showed a greater length of the right parietal and right occipital lobes by 12.2% and 16.4% respectively compared to female infants (Baibakov SE and Fedorov VP, 2010). Gilmore et al. reported significant differences in the growth pattern of the cortical lobes with the occipital and parietal regions growing significantly faster than the prefrontal region (Gilmore JH et al., 2007) Furthermore, this study demonstrated that the brains of neonate females present more asymmetry in both regions compared to males (Gilmore JH et al., 2007).