Early development of the forebrain and midbrain: a longitudinal ultrasound study from 7 to 12 weeks of gestation

Abstract

The purpose of this longitudinal study was to describe embryonic development in vivo. Twenty-nine healthy pregnant women were examined five times with transvaginal ultrasound between 7 and 12 weeks of gestation. Brain structures such as the hemispheres, the choroid plexus of the lateral ventricles, the diencephalon, and the mesencephalon were identified and, if possible, measured. It was possible to identify the cavities of the hemispheres, the diencephalon and the mesencephalon during week 7. The choroid plexus of the lateral ventricles became visible during week 8. The growth of the length, width and height of the hemispheres and the choroid plexus of the lateral ventricles was curvilinear, that of the mesencephalon and diencephalon was linear except for the width of the diencephalon. The width of the diencephalon, the future third ventricle, was 1.1 mm during week 7. It decreased to 0.8 mm at 12 weeks. Apart from the rhombencephalon, the cavity of the diencephalon was the large dominating brain structure during embryonic development. In early fetal life the cerebral hemispheres took over this dominance. The study was in full agreement with descriptions in the embryological literature, both concerning the anatomical features and their chronological formation.

10.14744/nci.2014.84803

“…Cyr et al [12] described the sonographic appearance of the fetal rhombencephalon in 25 fetuses aged between 8 and 10 gestational weeks. Blaas et al [13, 14] were able to demonstrate the development of the fetal brain from 7 to 12 weeks. Since the beginning of these studies, improvements in ultrasound equipment with increasingly widespread availability have allowed the investigation of the fetal brain in a much larger population, during the routine first-trimester scanning [12-14].…”

Investigation of early pregnancy

“…[6][7][8][9]16 Of extraembryonic structures, especially the yolk sac and the amniotic sac show a growth pattern that is closely related to embryonic development. [6][7][8][9]16 Of extraembryonic structures, especially the yolk sac and the amniotic sac show a growth pattern that is closely related to embryonic development.…”

The central nervous system. Normal development and development anomalies. Ultrasound diagnosis in early pregnancy

“…3. Besonders gut läût sich mit transvaginalem Ultraschall das embryonale Gehirn untersuchen, da die groûen, ¹zystischenª Hirnventrikel relativ einfach abgebildet werden können.…”

“…Die Falx cerebri entwickelt sich jetzt aus diesem Bindegewebe[10] und wird allmählich im Ultraschallbild sichtbar. Sein Lumen ist immer noch relativ groû[3,22]. Die echogenen Plexus chorioidei wachsen schnell und füllen die Seitenventrikel aus.…”