Sonographic Evaluation of Normal Anatomy of Fetal Central Nervous System in Mid-Trimester


The central nervous system is a common site for congenital anomalies. Neural tube defects (NTDs) such as anencephaly, encephalocele and spina bifida are among the most common central nervous system congenital anomalies. They result from failure of closure of the neural tube during embryonic development. The neural tube formation starts during the fourth week (22 - 23 days) after fertilization and fuses approximately between the days 25th and 27th. Most of NTDs result from genetic factors and environmental factors which are poorly understood. Diagnostic sonography can show a detailed visualization of the fetal intracranial anatomy such as the cerebral hemispheres, midbrain, thalami, and lateral ventricles. They also can measure the ratio between lateral ventricular and cerebral hemispheric width. It might show as well, the ratio between gestation, the rapid growth of the cerebral hemispheres and the expansion of the cerebral ventricles. The ultrasound during pregnancy plays a prominent and influential role in the prenatal evaluation of the central nervous system. It gives an excellent window for viewing and evaluating the fetal central nervous system during the second trimester through the lateral ventricles and transthalamic view, thus effectively contributing in the diagnosis and treatment of its congenital anomalies.

Share and Cite:

Alsharif, M.H.K., Elamin, A.Y., Mohamed, D.A. and Taha, K.M. (2015) Sonographic Evaluation of Normal Anatomy of Fetal Central Nervous System in Mid-Trimester. Forensic Medicine and Anatomy Research, 3, 32-38. doi: 10.4236/fmar.2015.31007.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Sadler, T.W. (2011) Langman’s Medical Embryology. Lippincott Williams and Wilkins, Philadelphia.
[2] Myrianthopoulos, N.C. (1977) Epidemiology of Central Nervous System Malformations. Handbook of Clinical Neurology. Elsevier, Amsterdam.
[3] WHO (2005) Regional Consultation towards the Development of a Strategy for Optimizing Fetal Growth and Development. WHO, Cairo.
[4] Barker, D.J., Gluckman, P.D., Godfrey, K.M., Harding, J.E., Owens, J.A. and Robinson, J.S. (1993) Fetal Nutrition and Cardiovascular Disease in Adult Life. Lancet, 341, 938-941.
[5] Schwarzler, P., Senat, M.V., Holden, D., Bernard, J.P., Masroor, T. and Ville, Y. (1999) Feasibility of the Second- Trimester Fetal Ultrasound Examination in an Unselected Population at 18, 20 or 22 Weeks of Pregnancy: A Randomized Trial. Ultrasound in Obstetrics and Gynecology, 14, 92-97.
[6] Goldberg, J.D. (2004) Routine Screening for Fetal Anomalies: Expectations. Obstetrics Gynecology Clinics of North America, 31, 35-50.
[7] Blaas, H.G., Eik-Nes, S.H., Kiserud, T., Berg, S. and Angelson, B. (1995) Three-Dimensional Imaging of the Brain Cavities in Human Embryos. Ultrasound in Obstetrics and Gynecology, 5, 228-232.
[8] Bronshtein, M. and Zimmer, E. (2001) Transvaginal Sonography of Normal and Abnormal Fetus. The Parthenon Publishing Group Limited, Casteron Hall.
[9] Romero, R., Pilu, G., Jeanty, P., Ghidini, A. and Hobbins, J.C. (2002) Prenatal Diagnosis of Congenital Anomalies. Appleton & Lange, Norwalk, Connecticut/San Mateo.
[10] Johnson, M.L., Dunne, M.G., Mack, L.A. and Rashbaum, C.L. (1980) Evaluation of Fetal Intracranial Anatomy by Static and Real-Time Ultrasound. Journal of Clinical Ultrasound, 8, 311-318.
[11] Achiron, R., Yagel, S., Rotstein, Z., Inbar, O., Mashiach, S. and Lipitz, S. (1997) Cerebral Lateral Ventricular Asymmetry: Is This a Normal Ultrasonographic Finding in the Fetal Brain? Obstetrics & Gynecology, 89, 233-237.
[12] Nicolaides, K.H., Gabbe, S.G., Campbell, S. and Guidetti, R. (1986) Ultrasound Screening for Spina Bifida: Cranial and Cerebellar Signs. The Lancet, 328, 72-74.
[13] Katorza, E., Duvdevani, N., Jacobson, J.-M., Gilboa, Y., Hoffmann, C. and Achiron, R. (2014) Coronal Approach for Measuring both Fetal Lateral Ventricles: Is There an Advantage over the Axial View? Prenatal Diagnosis, 34, 279-284.
[14] Filly, R.A., Cardoza, J.D., Goldstein, R.B. and Barkovich, A.J. (1989) Detection of Fetal Central Nervous System Anomalies: A Practical Level of Effort for a Routine Sonogram. Radiology, 172, 403-408.
[15] Falco, P., Gabrielli, S., Visentin, A., Perolo, A., Pilu, G. and Bovicelli, L. (2000) Transabdominal Sonography of the Cavum Septum Pellucidum in Normal Fetuses in the Second and Third Trimesters of Pregnancy. Ultrasound in Obstetrics and Gynecology, 16, 549-553.
[16] Timor-Tritsch, I.E., Monteagudo, A. and Mayberry, P. (2000) Three-Dimensional Ultrasound Evaluation of the Fetal Brain: The Three Horn View. Ultrasound in Obstetrics and Gynecology, 16, 302-306.
[17] Chitty, L.S., Altman, D.G., Henderson, A. and Campbell, S. (1994) Charts of Fetal Size: 2. Head Measurements. British Journal of Obstetrics and Gynaecology, 101, 35-43.
[18] Chudleigh, T. and Thilaganathan, B. (2004) Obstetric Ultrasound: How, Why and When. Churchill Livingstone, London.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.